Shooting star

Currently, it is proved that the shooting stars such as solids, as well as meteorites, they fall into Earth's atmosphere from outer space, and breaking into it with the escape velocity, begin to glow. Height, where they light up and die, different, one can assume that at the time of occurrence, they are within 15 miles of the earth's surface, and at the time of extinction - 11 miles. Light phenomena and in this case depend on the air that is compressed and warms up quickly flying across his body for reasons of extinction may be different: either the body breaks down into dust because of the high temperature, and perhaps even burns or goes again from within the Earth's atmosphere . In most cases, the stars are lonely at longer intervals, sometimes they are incredibly fast one after another. In 1799, 11 / 2 am on Nov. 12 in Kumano in Venezuela, Alexander Hum-bolt noticed on the eastern part of the whole firmament thousands of fireballs and shooting stars, all of whom flew in one direction, from north to south. Subsequently okazalod that such a stream of falling stars was seen across America from the equator to Greenland, and reached Germany. Area covered by them, stretched up to 1 million square meters. miles. At first, astronomers did not pay sufficient attention to this phenomenon, but it subsequently filed a common interest, it was soon proved that certain periods of the year and are characterized by well-known night then stronger, then weaker falling stars.

The shape and size of the Earth

In the first, childish ideas, the earth is flat all around, from all sides washed by water, but already at the classical peoples, at least among scholars, gradually evolved belief in the sphericity of the Earth. With the names of Pythagoras, Parmenides, Archimedes, Ptolemy binds the thought of his first appearance. In the Renaissance of Sciences in the west this idea was resurrected, and a deep belief in the certainty of its forces Columbus to go on a long journey to the unknown West and find a new way to India and finally, the first trip around the world Magellan was undeniable and compelling evidence of the sphericity of the Earth. But this curiosity of a man was not yet satisfied: he set out to determine the magnitude of the globe. Already over 200 years before Christ. this important task by scientists whose work belong to the brilliant studies of antiquity and whose name in the history of science is surrounded with undying glory. This - Athenian Eratosthenes, the librarian at Alexandria. With the most insignificant means, exclusively guided by his genius, he first took measurements, which we now call the measure a degree meridian. Determine the magnitude of the Earth by measuring one of the great circles of her all over, of course, impossible to find astronomical by geographic location of the two seats and the distance between them to measure directly. Based on these data will be possible to calculate the magnitude of one degree. Eratosthenes measured the length of the shadows that cast on the ground perpendicular to the pole (gnomon) measurement was performed in Alexandria, the longest day of the year at about noon, it was already known that at the same time under the Tropic of Siena (now Aswan) in Upper Egypt, the sun is at its zenith, and so upright standing subject does not cast shadows.

Mezosiderity

Among the latter are the most common type of chondrites, are composed of fine-grained gray or black mass, resembling volcanic tuff, in her apparent peculiar beads and grains of olivine, bronzite, nickel iron, etc., the origin of these grains has not been elucidated. In terrestrial rocks chondrites are of no close resemblance, on the contrary, some other meteorites, especially the so-called Eucrite consisting of anorthite (lime feldspar) and augite, are many similarities with rocks of the Earth (for example, with some lavas of Iceland). The following is called a meteorite Chassignite consisting of olivine with the included chromium Zheleznyak, it is no different from almost anything quite common in the land of olivine rocks. We've gone too far, if seniority list all the less important modifications of meteorites, we give is only one kind of them, drastically different from the others, and especially interesting by its composition, the so-called carbonaceous meteorites, their example may serve as meteorites STE France (1806), Kolda, Bokkefelda (Cold Bokkefelda) in the Cape Land (1838), Kaba near Dobretsina in Hungary (1857) and Orgeylya in France (1864). They represent the earthy crumbly mass and contain compounds of carbon with hydrogen and oxygen, the nature of these compounds were not determined. Of particular interest are meteorites because of their similarity to the formations, found in the earth by comparison we can make a lot of important conclusions about the properties of our planet, are not subject to direct observation.

INSIDE OF THE GLOBE

According to Nordenshelda, at this point there pass two basalt veins, and they surround a piece of native iron and the top covered with numerous small sequins iron. The chemical composition of metal is a great similarity with meteorites: it contains nickel, and troilite. Individual pieces of iron were surrounded eucrites, mineral, and equally the found in meteorites and on earth. Nordenskiold, describing his find, offered two explanations for its origin: either the basalt at its eruption extracted from inside the Earth mass of iron and brought them to the surface, or during the eruption of basaltic meteorites fell a lot, and the mass of iron and eucrites have been introduced into soft and not had time to otverdet More basalt. The Swedish government sent a new expedition in Ovifak to take out large pieces and put them to research that Nordenskiold could not produce. Small iron sequins on the basalt was difficult to ascribe meteoric origin; Stenstrupa observations showed that the distribution of iron is limited solely Ovifakom and that in other places on the island Disko basalts contain only small amounts of this metal, apparently non-cosmic origin. Iron Ovey the FAQ resulted probably from the interior of the Earth and is a sample of the heavy mass, which implies the certainty of the value share of the earth: so that the meteorites represent a striking similarity with those rocks, which form the interior of the globe. The facts with which we are acquainted, are extremely important: meteorites show that comets are composed of the same elements and in most cases from the same minerals and rocks that we find on earth and especially its depth, spectral analysis undoubtedly found that the same earth elements are part of the Sun, stars and nebulae.

Compression of the earth's ellipsoid. RUSSIAN degree MEASUREMENT

These works have been especially developed since then, as proposed by General Beijer in Berlin zavedyvanie they took the international geodetic commission. Although the accuracy is increasing and research every day to expand, but the results do not meet expectations. Instead, the alleged coincidence with the calculated figures obtained strong deviations. Based on observations of vibrations of the pendulum contraction of the Earth at the poles = 7288 - Bessel same in 1841, on the basis of 10 known and then they randomly selected degree measurements, calculated the following quantities: the radius of the Earth from the center to the equator ........ 6.377 379 m radius of the Earth from the center to the pole ......... 6.356 079 m compression at both poles ............ 21.735 m radius at the equator ............... 6.378 190 m radius at the poles ............... 6.356455 m Compression ................... 21.735 m. At first sight these differences seem insignificant, but if we take into account that a slight change in the Earth radius at 1 m entails a change in the Earth's surface almost 3 square meters. miles, it becomes clear that the obtained differences are not devoid of deep meaning. They can not be explained by the inaccuracy of measurements and calculations, on the contrary, is gaining the conviction that different results are caused by the properties of the Earth's surface. With all the geodetic measurements is very important position the plumb line. Assuming that the mass inside the Earth are uniformly distributed, have long thought that it was at any given point perpendicular to the ideal of the globe.

Deviation of the vertical line

The exact definition of the Earth's gravity, made Shschernekom in the Tyrol and elsewhere in the Alps, the Czech Republic and in the Carpathians through an improved pendulum gave surprising results. The calculation of Helmert made on the basis of these data showed that the effect of solid Earth masses to a greater or lesser extent, destroyed due to the lower density of the earth's crust under the continents. Apparently, the large accumulations of mass on the surface, forming the mountains and continents meet in the Earth's well-known shortcomings of mass (Massendefecte). Further studies have confirmed this assumption and on the other hand was forced to assume that under the seabed are more dense mass that and violate the correctness of the pendulum on oceanic islands. Therefore, the prism with the same cross-section cut at a certain depth and extending to the surface of the Earth, will have the same mass regardless of where in they are taken. Opening This recovery has raised the credibility of the geodetic measurements. Aside from errors of observation, the accuracy of the results could affect only those deviations, which are a consequence of imperfect compensation at different points of the Earth. All studies have shown that these deviations should not be significant, so the actual surface of the earth, perpendicular to all the observed perpendicular lines, or as they call it, the surface of "geoid" may not differ significantly from the ideal ellipsoid. With regard to its oblateness, at the present time, we can say that it is between V298 and 7zoo-Surface "the geoid", depending on the mass distribution in some places should be lifted above the ellipsoid, while in others - to descend, but to a minor degree.

Cteklovatye rocks

Microscopic structure of volcanic products also varied. Some lava formed at solidification of glassy rocks, are in most cases trahitovye lava various localities. They usually represent highly lustrous masses with conchoidal fracture when broken, and give a translucent shards with sharp edges. Often they are black, rarely dark-brown, gray and green. This so-called obsidians: and they do not represent pure volcanic glass, and under the microscope can be seen in their bulk of many small crystals. Obsidian lava known in Europe for the Aeolian Islands north of Sicily, and in large numbers in Iceland, in addition, in Armenia, in the Canary Islands, some of the West India Islands, Mexico, the National Park Connect. States on the river Iellouston, and Java is a lot of rich silica glassy lavas. However, the vitreous structure of the lava is generally the exception, especially the rarely seen it from the poor in silica basaltic lavas. The edges of the basalt veins, which they are adjacent to a neighboring rock (so-called selvage), sometimes composed of basaltic glass - tahilita. The same structure was also observed in the lava flow Mouth of Hell (Gueule de l'Enfer) in the Department Ardem in central France, the lower parts of it, located directly on the ancient rocks (gneisses), have glassy structure. Modification of glassy basalt lavas in large numbers are on the island of Hawaii, is not alien to those of education and the influx of western North America. Reason, by which the lava acquire vitreous structure is not completely known to us.

Weight of the globe

Ways to such studies are quite different. The first measurements were made Gyuttonom and Maskelyne (Maskelyne) in Scotland in 1774 - 1776 years. Above it was mentioned that the mountain attracts hanging weights and therefore deviates somewhat from the vertical position of the filament, supporting her, if we know the size and weight of the mountain, we can calculate the weight of the Earth, which determines the vertical position of the filament. For the experiments, was elected Shehallin mountain in Scotland, near Perth, measuring the volume of this mountain and determining the average density of its constituent species, Gyutton Maskelyne and calculated its weight. Astronomical position was found by a vertical line, and directly determined by a plumb-line deflection to the north and south of Shehallina. Thus get all the numbers needed to solve the problem, calculations showed that the Earth is 4,7 times heavier than an equal to her largest ball of pure water or, in other words, the specific gravity or density of Earth = 4,7. However, found the number was inaccurate. In 1856, James (James) repeated the experiment over the mountain See Arthurs (Arthur's Seat) in Edinburgh and found that the density of Earth = 5,3. This value is more close to the truth. But in general the definition of weight of the Earth by the deviation of the vertical line should be considered unreliable: measure the volume of a large mountain to find the location of the center of gravity and density of rocks, its components, not with sufficient accuracy.

Flaming of the Earth's core

Moon and to a lesser extent the sun produces attractive effects on the equatorial part of the Earth and change the direction of Earth's axis. This is an extremely slow movement and is known in astronomy under the name of the process, or the equinoxes. Phenomenon should occur differently depending on whether the Earth is a solid ball surrounded by a thin crust is she, or consists of a thick shell and a relatively small nucleus. Hopkins failed to prove that observed in the process actually corresponds to the solid crust of approximately 170 - 215 Geography. miles. From this he concluded that the entire globe can be considered as a rigid body, which only exist in places cavities filled with flaming mass. Rightly pointed out that the calculation of Hopkins' stand on false grounds, the molten mass of the earth's innards can not be a real fluid, as this allows a scientist, she is so thick and sticky, the particles move with its large internal friction, in addition, there is friction on the boundary contact between the molten mass from the Earth's crust. Consequently, the conclusions of Hopkins's not true, even in the case of very rapid rotation, the more they do not apply to such a slow motion as a phenomenon of the procession. Poisson suggested that the solidification of the Earth began from the inside and that is why our entire planet is a solid mass. The process of cooling it provides as follows: on the surface of the Earth, situated in the fiery liquid, formed by cooling of solid blocks, exceeding his weight surrounding liquid, they fall down.

The thickness of the crust and the state of the interior of the Earth

In any case, at some distance from the surface, at depths that compared with the diameter of our planet is very small, dominated by an extremely high fever. If we assume that geothermal degree = 33 m, then at a depth of 66 km, 9 miles or incomplete, there must exist a temperature of 2000 °; it is enough to melt all the rocks, at least under the conditions that are observed on the ground surface . Should we conclude from this that within the Earth is flaming mass? And if so, at what depth it is? These questions are among the most important but most difficult in the whole of geology. Solution to their science is a long time, but a satisfactory answer and impossible at the present moment. Already Descartes and Leibniz admits the existence of the fiery liquid core inside the Earth, but only the Laplace, Fourier, and Cordier scientifically substantiated this hypothesis. Temperature rise toward the center and the existence of hot springs confirm it, and lava pouring out of volcanoes, directly indicate the existence within the Earth's molten mass. The similarity of the composition of lavas in various parts of the Earth causes the attribute to them a common origin from a single large central mass and makes it impossible for an explanation of volcanic phenomena of local processes. During all periods of Earth's history, to the most recent times, there are strong fluctuations of the continents that point, apparently, to exist beneath a rolling basis. Compression of the Earth at the poles is also proof of the original fiery-liquid state of the Earth: a solid body could never get a form that corresponds to the shape of rotating liquid body.

Age of the Earth

These calculations produced the famous physicist William Thomson, of the inaccuracy of data, the figures obtained by this scientist, vary within wide limits. Data on which he based the calculations were: the temperature at which solidification of the Earth began, the thermal conductivity of rocks and geothermal degree. Since none of these values ??is exactly unknown, in one case, Thompson took the largest amount in another the lower and middle in the third case. This way, he came to the conclusion that since, as the Earth began to harden, flowed at least 20 million and not more than 400 million years, the most probable number of turns lying in the range between 90 and 200 million years. Too many think that these figures are likely. It would be very important to achieve an unconditional definition of time in the history of the Earth, and therefore it is understandable that the thought expressed in such a respected scholar, once gained many supporters. But the math can give accurate results only when they are put in the bottom right data, with a lack of recent Math powerless. Calculations Thomson would have the right to universal recognition only if all three values, put them in the ground, were true, and if there was no fourth condition, which would have been overlooked. First, perhaps, could have been, and fix it, but in the calculations Thomson is not satisfied and the second condition. In considering the cooling of the sun, we saw that with a reduction of its mass develops heat, which compensates losses occurring as a result of radiation and the same should be true of the earth: and it is the beginning of cooling was subjected to strong contractions, the heat is released and the process of cooling slowed .

The temperature of the earth's innards

On the physical properties of bodies, if such exceptional circumstances, we have no idea. Based on laboratory studies, we can only say that the temperature of the Earth's core lies above the critical temperatures of all bodies. As we already know, this is called the critical temperature at which the gaseous body can not be translated into a liquid state even at very high pressures. Hence, if the interior temperature of the earth is calculated correctly - the Earth's core, despite the high pressure, can not be a liquid: it is a special form of the gaseous state, which can be called supercritical, and for all its density possesses the property of gases to fill the space in which it located. In the center of the Earth all the chemical states must be expanded, and the elements in a free state, the direction of the surface pressure decreases, and chemical compounds are formed again. Around the nucleus, which has the supercritical temperature is, apparently, gas shell, it gradually turns into a liquid mass, then placed a plastic substance that is a transition to the solid crust (the lithosphere). This idea of ??a terrestrial insides, of course, is not devoid of a hypothetical nature, but it satisfies the physicists and to some extent facilitates the geologists explanation of volcanic phenomena and processes of mountain building. Nucleus, located in the supercritical state, must possess a high density, and therefore this theory in its main features coincides with the views of Thomson, who admits the existence of the solid Earth's core.

Products of volcanic eruptions

Small streams have a stand density of honey, but in most cases, clutch their particles is much greater, at least, it takes some stress to stick a stick into the lava mass, and deepening that occurs at the same time, it remains for a full hour. Many streams can be compared with the semi-liquid cement. In some cases, as is the Humboldt and Bussengo in South America, they are not completely molten mass, and are a mixture of liquid magma from solid chunks. Speed ??of movement of the lava varies, depending on its density and the slope of the terrain where it makes its way. Relatively small lava flows that poured down the steep slopes, move forward very quickly; stream ejected Vesuvius on Aug. 12, 1805, raced up the steep slopes of the cone with amazing speed and in the first four minutes, U2 made 5 km> and in 1631 another thread the same volcano reached the sea in one hour, ie, was at this time of 8 km. Especially liquid lava stand open basalt volcanoes of the island of Hawaii, before they are mobile, that the cliffs form a real lavopady and can move at most a negligible slope of the soil, even in Mr. repeatedly observed, as these lavas were 10 - 20 and even 30 km per hour. But such a quick movement belongs in any case to the number of exemptions, even the lava, which saw Scrope in 1822 and which is within 15 minutes of time to get down from the edge of the crater of Vesuvius to the foot of the cone is not normal. At Etna lava movement believe is a quick, if it occurs at a speed of 1 km in 2 - 3 hours.

Solid state, the earth's core

The reason for the solid state of the Earth's core seen in the strong pressure, which, despite the heat, does not permit fusion. Volcanic eruptions apparently contradicted this assumption, but Reier eliminate any misunderstandings, he showed that the magma and solid, while under intense pressure, capable of erupting. If a solid mass located above the cracks and thereby decrease the pressure, the magma will move to a liquid state and will break out. It presupposes the existence of liquid magma or in the form of restricted basins, or as a continuous intermediate layer between the solid crust and the solid core. This theory was developed by Hopkins and after the promulgation of the striking deviations of the Earth's gravity in the Himalayas again gained many supporters among the British and French scientists. Pratt and Faye (Faye) explain the increase in the Earth's gravity on oceanic islands larger capacity solid crust that is located above the intermediate fiery liquid layer. As you know, at the bottom of the ocean dominates the constant temperature close to 0 °; at great depths it reaches - and even F - 2 ° C. Because of this oceanic region lost a lot of heat, and the crust on the ocean floor quickly thickens, but by Faya and compacted. To explain the compensation of the masses, which, as we know, takes place on the earth's surface, Faye admits that the dura mater of the upper layers of dense liquid intermediate layer. Views of the English astronomer Erie generally similar to opinions Faya, but in particular those representing some differences.

Solid crust of the lava flow

It is hard to imagine a more wild and gloomy picture than the one that presents us with the outer surface of the flow of blocky lava. Another peculiar form of the so-called wavy lava that is less common, but well known to every visitor to Mount Vesuvius. The road from the rubber to the observatory is laid at considerable length on this lava, the latter thrown Vesuvius in 1855, The Protection of these threads is not broken into pieces, and is a solid mass, irregular surface of which resembles a sort of his intestinal plexus.

Lava cores

As a result, the individual prisms differ in both sides of the center and are arranged obliquely in the form of barbs pen. Investigating of volcanic rocks, bare action of the destructive processes, it is often difficult to decide whether we are dealing with the remnants of veins or thread. Location columnar separately allows us to understand sometimes in this difficult question, so, for example., Vertical pillars on the banks of the Colorado River have the location, which is characteristic of individual lava flow on the contrary, cirrus formation Gumboldtovoy rocks on the shore of Elbe Aussiga (mouth) in the Czech Republic are excellent example of the structure, which have cores.

The relief of the earth's surface

Of course, all are well aware that represent those colors. Blue - it's waters, green - plain and lowland, yellow - the various hills. And where yellow turns to brown, it indicates the highest mountains on our planet. Similarly, the need to understand the symbolism and the blue and green colors. Where the blue caused darker - deeper and where lighter - smaller. Well, and where it goes into the blue, there are very great depths of the planet. Hence, at the bottom of the oceans and seas are - as well as on the land surface - its hills, hollows and valleys. Only they are a relief of the seabed and ocean floor. Likewise, the land surface. It would seem that the plain - a flat, level place. But in fact, and it has a huge number of various small and big hills and depressions. Besides plain crossed by river valleys and deep ravines. These ravines are sometimes steep slopes, covered with low hills. All this creates a truly magnificent scenery in many parts of the world. But there are mountains where the terrain and there are surprising metamorphosis. Breathtaking majestic peaks covered with snow caps, replaced by deep steep gorges. In the mountains you will ever encounter is with the ups, the downs with. They create extremely complex terrain. This here it is, the relief of the land. And as you can see, it is very complex and diverse. It includes a variety of forms - from the giant (continents, oceans) to the smallest. This is the most minor irregularities and complex rock formations.

Hypothesis Sartorius von Valypersgauzena

To establish some perspective on this subject is extremely difficult, but among all the hypotheses explaining the phenomenon, the most likely hypothesis Sartorius von Valypersgauzena. According to the commonly held view Earth was originally molten ball. Upon cooling, the latter a variety of substances were located closer to the center or away from it depending on their weight: heavy mass is concentrated in the center, lighter settled around him in a series of successive concentric layers. Since acid-rich silicates (normal trachytes) have a smaller specific weight, then they formed the outer layer of the original globe; poor are silica silicates (normal basalts) are located deeper. Thus the two areas from which the volcano gets lava lie on each other; trahitovye lava erupting from a lesser depth, basalt - more.

Fragments of rocks

These products rarely come across a new cone of Vesuvius, and in recent eruptions and the nonexistent, on the contrary, the ancient Vesuvius - Somme during their prehistoric eruptions, throwing out a huge number of such bombs. The latter consist in part of modern marine sediments from Bivalve and gastropod shells, partly because of the gray limestone Cretaceous. In the Apennines and the mountains of Sorrento similar form thick layers of limestone, probably they occur also in the depth beneath Vesuvius. Ejected by volcanoes limestones have undergone significant changes, some fragments of them have turned into crystalline marble, some of them, due to the chemical action of lava on calcium carbonate, formed a number of curious and well-crystallized minerals. Most likely to be calcite, augite, mica, olivine, less vesuvianite, garnet, forsterite, humites, sarkolit, Mayon, Melita, leucite, nepheline, sodalite, hauynite, wollastonite, and many others. Vesuvius is one of the famous deposits of various minerals.

Volcanoes of Europe that lie outside of Italy

In the history of geology theirs is an extremely important role: due to the detailed study of these volcanoes have been resolved a bitter dispute about the origin of basalts. Central plateau of France rises about 1000 meters above sea level and consists of ancient crystalline rocks, mainly granite. In some places there are here and freshwater Tertiary sediments, rises above them the latest igneous rocks, which by their location, and partly by age fall into two distinct groups. On the one hand, we find here large volcanic centers that occupy significant space and form a whole system of mountains are ancient volcanoes of the Tertiary period: the influence of the erosion of the crater collapsed, and yet gone any outward signs of their volcanic origin. On the other hand, we found a huge number of small volcanoes. Page 1 of 2 | Next page

Properties of lava

Much more properties and composition of the lavas vary with certain regularity, first released a lava, then another. Usually preceded by basaltic trahitovye products. An example is Vesuvius: Somme is composed of rocks rich in silicic acid, on the contrary, during the latest eruption ejected poor silicic acid leucite lava. In some cases, after a period of basaltic volcanoes emit a short time trahitovye lava. In Hungary and in western North America Rihtofen a complicated sequence of different lavas. In these countries, products of ancient eruptions have strong basic character and are composed of propylene and andesite, then the acidity increases, trahirovye ejected lava and strongly acidic rhyolites, and finally again the basalts. This remarkable sequence, named after its discoverer scientist, observed in Japan, the Aeolian Islands and in other areas. Thus, in most cases the products emitted by volcanoes, are subject to known shifts. What is the reason for this phenomenon? Apparently, in the depths from which erupt lava, there are two dissimilar materials, occupying different regions: the same volcano lava gets from different areas. In most cases you can assume the existence of two regions: one delivers the lava rich in silica, the other - her poor, lava, occupying an intermediate position in its composition, are due to mixing. This idea is supported by research over the Bunsen lavas of Iceland: it showed that on this island are extremely representatives of both kinds. Some he calls normal trahitovymi rocks, while others - the normal pyroxene rocks (it would be better to call them basalt).

Telluric and sidereal forces

Under the influence of solar heat evaporates water, falling rain and snow, movement of water in the form of key rivers and ocean currents, the sun as we are obliged to alternate cold and heat, air movement and the existence of flora and fauna, which in turn turn, is an important figure in geological changes. The moon with the sun causes the existence of high and low tides of the sea. The activities of these forces is reduced mainly to the following: all high, acting on the Earth's surface is destroyed, debris knocked down in the valley, plain, sea, and deposited there. Different character are the telluric forces: in the foreground are of volcanic phenomena, earthquakes, converting processes - in the broadest sense of the word. All these grand phenomena can not be reduced either to the solar heat, and the attraction of nearest celestial bodies: they obviously are in connection with the processes inside our planet. Result of their activity is already quite different: the volcanic forces push the majestic cone of the mountains and carried out of the depths to the surface of lava, rocks, ashes orogenic processes required appearance large mountain chain, penetrates our continents, and finally an earthquake occurring as a result of moving parts of the earth's crust along the lines of fractures, are among the phenomena which not only reduces jagged earth's surface, but even increase them. Thus, education forms the Earth's surface involves two groups opposing each other activists: telluric forces reportedly Earth bumps cause the formation of highlands and lowlands, sidereal same forces align, flatten it, shape the earth's surface at any given moment is the result of equilibrium, which is established at some time between those and other figures.

GEOLOGICAL HISTORY

Was this change in local, or does it extend to the entire organic world, can not be solved by studying only the area: it is necessary to make observations in the largest possible number and in different localities. Such a comparative study of fossils shows that the distribution of the latter in groups of sedimentary rocks is not accidental and is subject to certain laws: the known remains of living organisms are found in certain strata, and in most cases the order of their successive appearance of the same in different countries. Let us imagine one of those places that are rich rocks containing fossils: fast forward in the Swabian Jura. Marl, clay and limestone in the area, with a remarkable sequence located on each other, contain many fossils, here we find, for example, marls with numerous fossilized shells of ammonites, what are the Ammonites radians and jurensis. Under these marls are shale, they are already different kinds of the same resources, what are the Ammonites communis, heterophyllus and lythensis. Still lie below the layers of limestone with the Ammonites spinatus, followed by clay with Ammonites margaritatus. Investigating such formations in the west and east of the country, we always observe the same sequence of fossils. Observations of similar sedimentary rocks in northern Germany, France and Britain have shown that there are certain in exactly the same manner for the same kinds of fossil animals. Finally, and most remote countries of the world from us in India, America, etc., have repeatedly observed the same sequence in the deposition of sediments containing fossils.

The effect of water on the earth's surface

Solvent power of water, the increasing presence of more carbon dioxide absorbed by it, acts chemically on the rocks and makes them decay. Every drop of rain falling on the ground, underground every key, every stream and river are devastating, and the joint work of their much greater work of the sea, which beats the shore, also erode and destroy them. This blurring processes (erosion and denudation, as they are called) are among the most important geological figures. There is no such solid rock, which would not yield to their action, there is no mountain range, which would oppose them. All the highest mountains of the earth belong to the relatively recent geological formations: the mountain peaks, formed in ancient times, collapsed. Flowing water carves its bed of rocks, as it can be seen in the Colorado River. In this case, erosion is sometimes small, sometimes formed deep valleys, what, eg, the famous canyons of the Colorado River system: in some places the bed, washed the river in a very solid rock, it reaches depths of up to 6000 feet. Often accompanied by erosion of another very important phenomenon: on the sides of the river valleys formed terraces, which correspond to the individual or the period of the whole process, or owe their appearance to the existence of the beach strata of the more solid and permanent rock.

Blurring with the formation of valleys

But the same is repeated in significant amounts. For example, in the Alps in Shluderbaha, in the Tyrol, the so-called three teeth present in their three fantastic high pyramids balance of the whole system that once occupied the whole area. If the principal features of the earth's surface topography is determined by orogenic processes, in any case the details of it are the result of razmyvayuschey of water: in a few million years, she razed to all continents with the surface of the sea, if, on the other hand, was not restored and destroyed continuously. Not only flowing water, but ice is one of the leaders of destruction. Glaciers descending from the mountain heights into the valleys, as well as continental ice polar countries are destroying the rocks on which they lie, in the depths of his ice masses are fragments of rocks and repent of them in the so-called moraines. However, with respect to the role played in the history of the land of ice activities, opinions diverge. Anyway, he is one of the most interesting figures of geological changes. Layered rocks were deposited under water and buried in the mass remains of animals and plants that lived there or were there recorded. If these organisms are capable to preserve, but now we find their remains are called fossils to study the past is the subject of paleontology. Study them in many ways is difficult due to the fact that all the soft parts of them have disappeared, however failed to show that in the past era of land inhabited the huge number of extinct forms.

The temperature inside the Earth

The most famous example of this kind is the cellar of the Paris Observatory: thermometer, placed here Lovuaze in 1783 at a depth of 27.6 m, for 100 years consistently shows a 11,6 ° C. In the warm equatorial countries, where annual temperature fluctuations occur in a narrow range, this layer is already a constant temperature / at a depth of 6 m, the poles of the earth is frozen to a considerable depth. In Europe, the northern ice cap has a large distribution and only covers the northern coast of the mainland, but in Asia as we approach its eastern outskirts, he pulls over to the south and descends near the Baikal Lake to 53 °, and in the Amur River basin to 50 ° ie to the geographical latitude, which is Frankfurt am Main. Likewise, in the eastern part of the North. America at the Hudson Bay ice cover extends to the same latitude. With regard to the depth to which the soil freezes, then in this respect, gives an indication of the merchant Shergina well dug in eastern Siberia in Yakutsk, on the banks of the Lena, it 11b72 m at a depth determined by temperature - 3 ° C. If on the layer, which has an average annual temperature of the area, go down a borehole or shaft, then a significant increase in temperature. The first reports of this fact we find in the «Mundus subterraneus» («The Underground World") Kircher of Fulda. This is a remarkable essay appeared in 1662; in it, as has been stated above, we find a striking blend of deep knowledge and correct views with backward objections to the latest scientific discoveries.

These three types of rocks make up the crust.

This is especially seen in sedimentary rocks, which are respectively the dominant form of the seabed and all the great lakes, were deposited mostly in the form completely horizontal or approximately horizontal layers. Meanwhile, it is known that at great length the earth's surface layers have not kept this initial position: they are either inclined at an angle known, or have a vertical position, or, finally, twisted or bent in various ways. It is obvious that at a later time there were mass movements, which are produced in most cases, these violations, twisted seams and lifted them. These mass movements are now considered as a consequence of reduction of land under its cooling. Such violations are correctly positioned layers are observed not only in some areas: "orogenic forces" act in the same general outline for a considerable length, this is due to the origin of entire mountain ranges of the homogeneous structure: in them, regardless of the existence of some local secondary phenomena, we can trace the same location of the dominant tectonic lines.

Basic concepts of geology

Let us imagine that by this or that process, it will raise or lower the land of the sea, moved part of the seabed. Immediately the rain, cold, running water and other natural forces begin to work towards its destruction. Assume further that the creek or river bed in his proroyut risen from the sea of ??rocks. On each side of the channel formed bare a number lying on each other horizontal layers, and the lowest of them will again be the oldest in age. Carefully examining the rocks bare to the riverbanks, often can be found in these fossils of plants and animals that lived during the epoch of the latest rainfall and enthusiastic. Time of formation of fossils and the formation, in which they are obviously the same thing. Age of the rocks is determined by their sequence arranged on each other, we can conclude that the fossils, found in the lower layers, belong to the more ancient organisms, and those contained in the layers located above represent the remnants of the later population of the earth. No matter how simple this fact, its value before it is extremely important, it gives us an opportunity to judge the succession of living beings on earth, and from descriptions of individual fossils go to a coherent presentation of the history of the organic world. The basis of such studies is the systematic collection of fossils showing the sequence of strata in which they reside.

Times of Albert the Great

In the XIII century, in times of Albert the Great, this view gained many supporters in the west; fossils looked kind of like a game of nature, partly as they saw the first attempts of creation: before you begin to create living beings, nature makes them dead prototypes . Fallopian considered fossil mammoth teeth and shanks dish prehistoric man, found in Monte Testacho, near Rome, earthy concretions, and Agricola believed that shell, found in the mountains were formed from the viscous substance under the action of heat; in fossilized bones, imprints of leaves and fish it saw the remnants of animals and plants, hardened by means of special stone juice. Other fossils attributed to the formation of the influence of the stars. In the last century many adherents had a theory that assume that the sea breeze blows particular, causes the formation of rocks "figured stones". At least that is the origin attributed to a traveler, and the ruins of the marble statues of the city open to them in kireneyskoy desert of North Africa. It is incredible that such views could for so long. But the prejudice was rooted too deeply, and yet in this century had its adherents, a famous geologist examined the fossils are not born as embryos never organisms ancient periods. It is not difficult to understand how such opinions might arise in an era when there were still traces of the right historical outlook. In the whimsical patterns of agate and marble, with some imagination it is easy to see images of people, animals, plants, species, and anything you want.

Origin of layered rocks

Wherever there is water on the earth's surface - and above all at sea - these processes take place. Near the coast, through the accumulation of silt and sand are formed mainly of clay, marl and sandstone, where deposited bivalve shells or kornenozhek, or where the polyps are building their magnificent buildings, "the formation of limestone rocks. This gives the right to think that all the huge deposits of chalk and limestone in our mountains owe their origin exclusively of organisms: the most insignificant of them produce the tremendous action, tiny shells kornenozhek, and mainly Globigerina, in huge quantities cover most of the ocean floor, and microscopic study of limestone rocks shows that the same thing happened in the last period of life of the earth. Sedimentary rocks, as we have seen, owe their origin to the water. Solid as rock emerged by solidification of molten fiery mass. Processes by which once formed the granites, porphyries, trachytes, basalts, and many other related species, we can observe now in the work of the burning mountains, which is bringing to the surface the molten mass. A good example of such mountains is in Europe, Etna. Nature of the eruptions and the composition of volcanic products are the key to understanding the origin of rocks formed in the early periods of Earth's history due to similar processes, though under conditions significantly different from those we see today on the earth's surface. In part, this ancient lava flows, partly filling cracks, partly products of deep massive eruptions.

The subject of geology

Even before the article is attracted attention by some wonderful people, but their writings were scattered and had little influence, the mainstream views have been deprived of accurate experimental basis, the facts are not summarized. Werner - the father of geology: he gave her an orderly system, and a solid foundation, he created the school, and his name and teachings have spread wherever there are people interested in science. The new science was developed in complete dependence on mining and mineralogy, and was initially only their branch, or, at best, secondary science, without any right to independent existence. And a lot of time passed before such a view of geology and disappeared before they were defeated prejudices hindering evaluate a new direction. Meanwhile, from geology allocate another branch of science knowledge, which is just as well for a long time played a subordinate role, is the study of plants and animals that inhabited the earth in past periods, paleontology, as it is called, Cuvier and Brongniart were the same for her than for Werner Geology . In a short period of its existence both science evolving with extraordinary rapidity, and brilliance, and exhibit a number of outstanding researchers. Since then continuously flock valuable new facts and observations from all over the world, and their accumulation is so fast that outstrips the theoretical development of the sciences. Era, this is too far from us and our achievements are significant, but the close relationship between geology and paleontology, which existed at the beginning, has remained till now, and in most cases the same person who seeks to capture both the science, or at least parts of both .

Only if the Europeans were the pioneers?

It is home to one of the most advanced early civilizations on Earth. This country - China. Occupying a large part of the Asian land, China is one of its side is washed by the Pacific Ocean. It is therefore not surprising that since ancient times, Chinese have mastered the art of navigation. They were able to build ships for sailing the high seas, in the perfection of his time possessed skills to navigate the stars and even invented the compass. On their ships, they went to the shores of Korea, India, to Java, to come to the shore of Africa. Scientists cite evidence that the Chinese were on the coast of Central and South America. But they are also a lot of traveling by land. So, for example, were found the origins of one of the largest rivers of Asia - the Yellow River. Were investigated mountains and highlands in the western limits of their own. Empire. In traveling by land, probably the way the Chinese and the Romans crossed. After all, both empires were aware of each other and exchanged goods. Originated and operated the famous Silk Road. However, more intensive contacts prevented the nations of the earth through which this road ran, as they too were interested in trading profits. One of these people were Arabs, the indigenous inhabitants of the desert, nimble traders. Islam, the beginning of an era which is 622 per year, was so strong religion, that only a few centuries covered a vast territory. And scientists, and merchants now easy to travel freely to explain in Arabic, and everywhere meeting co-religionists.

The composition of meteorites

Up in meteorites proved the presence of the following components: silicon chlorine potassium sodium calcium aluminum magnesium manganese iron cobalt chromium Hydrogen Oxygen Nitrogen Sulphur Copper Tin Arsenic titanium carbon addition, Lockyer, by spectral analysis showed the presence in meteorites of strontium, barium, zinc , bismuth, and lithium. Thus, the composition of meteorites is less than a third of known elements on Earth. Surprising insignificance of this number can not be due to a small number of meteorites, no doubt, further tests show the presence in them and other items. Iron, magnesium and silicon are most common on Earth and take an important part in its composition. The same thing we see in meteorites, on the contrary, calcium, potassium, sodium and aluminum are found in meteorites, in relatively smaller amounts than on Earth, precious metals entirely absent, and nickel is much greater role than in rocks of the Earth. Despite these particular deviations, in general, meteorites are fully confirm the idea of ??the unity of the various world bodies - the idea inferred by spectral analysis. The data that we obtained by exploring through the prism light of the Sun, fixed stars and nebulae, brilliantly supported by the analysis of the debris of comets. But here we can go further: we can examine how these elements are grouped into simple compounds, minerals, and how minerals are made from meteor rocks. Studies that make up the great merit of the glorious mineralogist Gustav Rose, showed that most of the minerals included in the meteorites as the crystallographic form and are chemically quite similar to the minerals of the Earth.

Types of spectra

Please, leave a ray of sunlight through a prism, we obtain the third type of spectrum, to the naked eye it looks identical to the continuous spectrum of solids and liquids, but has a weak telescope can observe in it a few black lines and the study of the solar spectrum at very high magnification shows that he was suspended by a number of such lines. This phenomenon observed Wollaston, the exact same study it did Fraunhofer in Munich, chief of the dark lines of the solar spectrum, he noted the letters of the alphabet from A to H, between the lines, he noticed a number of others. Further, he showed that in the spectrum of the Moon and Venus are observed dark lines are the same as in the solar spectrum, on the contrary, the spectrum of the fixed stars is not all dark lines coincide with lines of the solar spectrum. Fraunhofer has already observed that the dark line of the solar spectrum, denoted by the letter D, is located on-site sodium line, but this important discovery was ignored, and only after 40 years it served as a starting point for wonderful research Kirchhoff. Noticing, in turn, a complete coincidence Fraunhofer line D with a line of sodium, he sought to explain this fact. It is known that a weak flame, being faced with a very bright light source casts a shadow of himself, if, for example, place a lighted candle in front of an electric lamp, there will be a shadow not only on the candles, but also from the flames. Before the slit of the spectroscope Kirchhoff raised slightly luminous flame of sodium, and behind - the source with a bright white light rays are the last on the way to the prism had to go through pre-pale flame of sodium, something happened, what to expect a scientist: got quite a continuous spectrum, only the yellow of his side, where is the line of sodium, or line D of the solar spectrum, was pronounced double dark band.

Aristotle

He said that various phenomena occur in nature is not to make known in advance the intended target: the rain is not to grow grain, and not to destroy him during threshing in the open air ; of body parts, not in order were formed to carry out certain goals in life: one of them at its inception have been appropriate, other - inappropriate, and only those survived who had a first property, while others have disappeared or are continuing to disappear. In addition, we find in Aristotle's understanding of certain geological phenomena. He talks about the dry lakes, the annual growth of deposits in the Nile Delta and talks about lifting and earth changes that occur so slowly that their results can not been noted by man throughout his life. But stagirsky naturalist was not equally happy in all his wit's end, and as for fossils, he expressed less plausible view than his predecessors. Incidentally, he remarked that the fossilized fish, found near Hercules in Asia Minor could be formed from the eggs left behind living in the lake fish. But one accidentally mistaken view can not darken the glory of a great man. He is not responsible for the fact that such ideas were eagerly caught up in the later period, and ranged all possible and impossible ways. Representations of Aristotle on the origin of the fossils have the most influence on medieval beliefs and formed the basis of hard exterminable errors: they held out for a thousand years, and found adherents even among the geologists of our time.

Earth's gravity

The density of the rocks composing the crust, an average of less than 2.7, limestone and dolomite, clays, sandstones, granites, porphyries, trachytes, basalts, schists have a specific gravity in most cases significantly lower than 3, only some basalts are slightly higher than this figure, even the lodestone of their relative weight is easier to Earth (4,9 - 5,2), heavy metals exceed his last density. If the masses that make up a significant part of the crust, so easily, it is natural to assume that at great depth is a heavy nucleus, consisting of the metals. When comparing the meteorite with the Earth, we saw that the existence of meteoric iron, and his relationship with igneous boulders Ovifaka in Greenland indicate the presence inside the Earth large amounts of this metal. It may well be that there are rich reserves of precious metals, which are out of all the known bodies have the highest weight.

Planetary system

We have shied away, if it were to prove how easy it implies all movements of the planets from the law of gravity and how the law opened the great Newton. We will get acquainted with the question empirically. All planets, except for some small asteroids, make your way around the Sun in ellipses, not circles, as it was supposed to Kepler, and as it is sometimes necessary to hear, even now, all these ellipses have a small eccentricity, a little respect to the equator of the sun, and have common focus, which coincides with the center of the sun. Leaving aside the dubious world, located between the Sun and Mercury can be considered the last of the nearest planet to the Sun, the average distance him from the sun equals 0.387 radius of Earth orbit, while its circulation around the Sun - 88 days, the diameter of 648 miles and weight 7k Earth's mass. Followed by: Venus, the average distance her from the sun equals 0.723 radius of the Earth's orbit, time of treatment - 224 days, the diameter - 1.616 miles, weight - 0.8 Earth masses. Earth, the average distance her from the sun about 20 million miles, while the treatment - the year that the diameter of 1.719 miles and weight 7z2zooo mass of the Sun, she is accompanied by satellite - moon. Mars average distance to a 1.524 times greater than the distance of the Earth, while the full treatment - 687 days, diameter - 909 miles and weight - 0.1 Earth masses. Mars has two moons, revolving around it in orbits relatively small radius. Distance to name a star from the sun and gradually increase correctly, and to watch Mars planet, known since ancient times, Jupiter.

The subject of dynamic geology

The modern form to define them by means of gradual changes. Further changes are made under the same laws. Each day entails changes: volcanoes continuously emit lava, ash and rocks, parts of the earth's crust moves along the cracks and produce earthquakes, rivers are solids made within continents, and repent of them on the seabed. Along with the many other personalities from day to day running of the destruction of some structures and over the creation of others. All these processes occur so slowly that for a short time, we do not notice them and even get used to think that the Earth remains in its main features intact. But are millions of years, and the result of gradual imperceptible figures are stately change the earth's surface. The study of these changes is the principal task of geology. All the phenomena occurring on the Earth's surface, composed of tumors, alteration and destruction of masses of its constituent. Geology examines the forces that produce these effects, and figures, with the participation of which they are made, and also studies the laws of the latter. Among the paths leading to the solution of this problem, the simplest and most accurate is to study processes occurring on Earth and accessible to direct observation, as well as to clarify those results, which will result in such processes over time. The main feature of modern science and is the introduction of this method. It was first proposed by Goff, author of "History of the natural changes the earth's surface» («Geschichte der natiirlichen Veranderungen der Erdoberflache»), and put into general use Lyayellem in his "Principles of Geology» («Principles of geology»).

Earth's internal heat

First of all, you need to find out the reasons why the temperature increases with depth. On this subject expressed by many different reasons: to explain the point to the chemical processes and the transformation of mechanical work into heat, assumed that the entire solar system passed through the warmer parts of the world space, and finally saw the cause of the phenomenon in the initial heat, which, according to Kant's theory - Laplace, Earth has at its separation from the Sun.

MARS

Therefore, for further comparisons, we must turn to our planetary system, representatives of which shine by reflected sunlight. As for the four outer planets - Neptune, Uranus, Saturn and Jupiter, the latter is not entirely true, recent studies have shown that these planets to a small extent, seems to possess its own light, they are in a slightly heated condition. You can not with any certainty say they represent are gaseous, solid or liquid mass, but in any case no doubt that their density is low. The atmosphere of these planets we have said in the chapter on spectral analysis, and even earlier in the description of the famous rings surrounding Saturn. Briefly mention here a kind of striped spots covering most of the surface of Jupiter. First thought of their education as clouds, but lately Barnard, on the basis of long-term observations, came to the conclusion that the surface of this planet is in a plastic paste-like state. Bands should be attributed to color changes that occur due to internal eruptions. If only this hunch is confirmed, then Jupiter will serve as an example of an ancient slowly descending sun. On numerous asteroids can say little: the greatest of them, especially on tracks for an open atmosphere. The huge interest is the observation of planets lying in the asteroid belt, and especially over Mars. Venus and Mercury, whose orbits lie between the Sun and Earth, have been less studied. Mars, the extreme of the four planets closest to the Sun, has two small satellites.

Photosphere, Chromosphere, Corona

In fact, the photosphere is surrounded by other shells, invisible under normal conditions: they are observed only when total solar eclipses in the form of a narrow red ring. Spectroscopic study of the latter shows that the upper layers it consists of a heated hydrogen and unknown on Earth element helium, which is characterized by a yellow line of the spectrum. In the lower layers proved the presence of some heavy metals in the vapor state. This emitting red light weight gas reaches 1000 - 1800 miles thick. Similarly, a flaming sea of ??fire, surrounds it all the sun and, because of its coloring, is called the chromosphere (hrytsa - color). Between the photosphere and chromosphere is a thin layer of gas. He has remarkable properties. If, during a total solar eclipse to send a spectroscope tube just at the place where the edge of the photosphere disappears behind the disk approaching the moon, then at the moment of total darkness in a tube spectroscope get rays emitted by the lower layer of the solar atmosphere, and offer the spectrum, characterized by the set of bright lines . Hence it follows that this layer consists of a vapor of all the metals that exist on the Sun. White light of the photosphere under normal conditions pass through this layer; here and soaking up the rays corresponding to the characteristic colors of metals, and in the solar spectrum appear dark Fraunhofer lines. Part of the solar atmosphere in which there is absorption of radiation, may be called converts layer (umkehrende Schicht).

State of the world body

As we already know, the spectra of these bodies are characterized by broad dark bands, the so-called arcades, and find features by which one can conclude that the presence in them of a significant number of chemical compounds. The temperature of the white and yellow stars is very high and prevents formation of the placenta, there exist elements in a free state. On the contrary, the process of cooling the red star has gone so far that a complete decomposition of the substance on them impossible. Variability of the brightness of these stars leads to the same conclusion, ie, to recognize the lower temperature: however, fluctuations in their brightness is not always explained cooled. On some of the stars under consideration, these changes are of the correct periodic nature and can be explained by the existence of large dark satellites, which in certain periods of the stars pass by, close and darken them. In other cases, we are probably dealing with a very strong development of the spots and maybe even the whole tough continents, here and there protruding among the fiery sea. Sometimes a gradual decrease in brightness of celestial bodies violated swift disaster. This makes us the sudden appearance of new stars. A famous example is the star Tycho Brahe, so named after a glorious Danish astronomer of the XVI century. One evening, to my surprise the inexpressible, Tycho Brahe observed near the zenith in the constellation Cassiopeia bright star of extraordinary size. And this was in November 1572.

Kant's theory - Laplace

We know the elements that make up the Earth, and must assume that they are also included in the composition of the Sun and rotating around it all the heavenly bodies. Actual proof of this idea should be a brilliant way to confirm the hypothesis, and Kant - Laplace, and if we can show that the distant fixed stars are composed of the same elements, it is likely it will be possible to assume that they are in the same relation to each other and to the Sun, as well as separate parts of the planetary system, ie, that all owe their existence to the disintegration of the huge space nebulous mass.

WHITE, YELLOW AND RED STARS Secchi

The planets do not have their own light, they reflect the sun's rays. Watching the world through a prism, we get the solar spectrum, but with those changes, which causes their atmosphere, some rays are absorbed, and the number of dark lines increases. In this way it is proved that on Mars and Venus, there is an atmosphere like ours. Jupiter found the atmosphere in which water vapor play an important role. In addition, the spectrum of its lines were observed whose value is not yet clear, and which in any case correspond to the elements, not known on earth, similar phenomena were also observed on Saturn. Our moon has no atmosphere, and the traces does not change the solar spectrum. Thus, spectroscopic studies of planets did not prevent a shortage of bright light, but even more surprising results concerning the fixed stars. Until Secchi (Secchi) and Vogel, the latter can be divided into three types: the first belongs to the white or bluish, stars, here is more than half of all the fixed stars: Sirius, Vega in the constellation Lyra, Atair in the constellation of the Eagle, Regulus in the constellation Leo , Rigel in the constellation Orion and the bright stars of Ursa Major (except a) are examples of this group. These stars are in a heated state of fear, under their atmospheric metal vapors have low absorption capacity, and the spectrum they observed only a trace of dark lines. The second group Secchi belong to the yellow star, they are homogeneous with our Sun. Examples include the Capella in the constellation driver, Pollux in the constellation Gemini, Aldebaran in the constellation Taurus and Ursa Major, Procyon in the constellation Canis Minor.

Milky Way

All the visible vault of heaven is surrounded by the Milky Way, which can be compared with the glowing white ribbon. Naked eye, it seems equally bright, but with a telescope can be seen in many parts of its countless small and tightly clustered stars. As for the rest of the sky, the vast majority of visible stars there and almost all the bright luminous body found near the Milky Way, the most well away from his side of the firmament poor stars. To explain this phenomenon admit that our planetary system represents one of the many parts of the big heap of stars that is shaped like a flat lens (lentil). If we look towards the more remote from us sharp edge of the lens, you notice a myriad of stars we call them the Milky Way, on the contrary, far from the last space will seem to us poor stars, as in this case, we direct the eye to the flat faces lens and see before him only a thin layer of stars. According to some estimates - of course, very rough - it can be assumed that the least remote part of the lens edge is from us by 79 the distance of Sirius, and the furthest at 497 (the distance of Sirius is 20 billions of miles). It is known that the sun do not preserve their position, but it has a forward motion, the latter, we do not notice, because the Earth as well as all the planets, taking part in it. Only careful observation subtle movements of the fixed stars enable us to establish this fact, it turns out that we rush to the constellation Hercules at a rate that fluctuates between 23 / 4, and 7 miles per second.

Meteorites in Europe

At first glance this number seems small, but if you take into account how small Europe is and how easily can go unnoticed fall of meteorites in the sparsely populated countries in the wild mountainous terrain, large deserts, forests, wetlands and in the dark stormy night, it becomes certain that the number of stones falling throughout the land, is extremely large. One can assume that, at least 1 / 2 of meteorites falling in this part of the world elude observation, in which case we find that on the whole earth falls in the year of approximately 600 - 700 of meteorites.

Meteorite from Grashina

At six o'clock in the east appeared a brilliant meteor, and with a terrible noise burst, heard the hiss and rumble, the earth dropped two stone blocks, and the sky was gray band is visible, like a pillar of smoke, she notes the following meteorite. Most of the fallen boulders fell on the field just before the plow, and crashed into the ground to "three cubits", both the meteorite was sent to Vienna, the smaller of them disappeared without trace, and the larger stores and on our time in the famous collection of meteorites Imperial mineralogical study in Vienna. Meteor Crash in Grashina for many reasons is one of the most interesting: it is the first phenomenon is one of those about which we have quite accurate and credible news of his contemporaries, in addition, he survived a meteorite, and finally it was first observed in almost all meteorites vidmanshmemovy figures.

Meteorite from l'Eglya in Normandy

In places far distant from each other, in Caen, Falaise, Pont AUDEMER, Verneuil, and Alencon, was seen in the clear sky a fireball, he quickly moved from southeast to northwest. Soon afterwards a loud explosion was heard: it was heard for thirty miles in France for 5 - 6 minutes for an explosion followed by several cannon strikes, they moved to a volley of rifles and ended in a roar of many drums. Meteor no longer seemed like a fireball, but as is often the case (eg, in Siena in 1794, the Princess of Hungary in 1866), he was surrounded by smoke and had a kind of clouds form of the latter represented by a rectangle, the larger side which was directed from east to west. The cloud that seemed fixed (it was moving toward the viewer), and only a couple of which it consisted, next explosion scattered in different directions. Apparently, the cloud is 1 / 2 mile from l'Eglya, toward the northwest at a very considerable height, residents of two areas, separated from each other on the whole French mile, saw him at the zenith at the same time. Throughout the area over which the cloud was, heard noise like the whistling stones being thrown from a sling, the Earth will cast a huge number of meteorites (3000), the area covered by them, represented by an ellipse, the length of 21 / g of miles and a width of 1 mile. The largest stones gathered on the southeast end of the ellipse, the finest in the north-west, the rest in the middle. Despite the huge number nizvergnuvshihsya stones, none of them had any significant weight: the largest weighed 11 / 2 fundamental.

The size and weight of meteorites

Another meteorite, found in Brazil, weighing 7,000 kilograms, the same amount it did not exceed 1 cu. meter, two lumps of iron found in Hupaderosa in Mexico and owned by one of the meteorite, was 4.65 meters long and 1.5 meters wide and weighed about 24 - 25 thousand pounds, weight metallic meteorites reach 200 - 300 pounds, in general, they rarely are heavier than 50 kilograms, and in most cases, weigh much less. Whole meteorite of small size are very rare, because of the difficulty of their search technique. After a meteor shower at Hesley, near Uppsala in Sweden, 1 January 1869, the white shroud of snow, dressing the Earth, has helped to find a small meteorites: found instances of extremely small size, the tiniest of them to be stored in Stockholm, weighs 0.06, the

Proceedings of the meteorites in the Middle Ages

Stone rain that occurred around Shleyzingena in Thuringia May 19, 1552, perekolotil a lot of windows and killed the horse of Prince Schwarzburg-Rudolyptadskogo. 4 th September 1511 as a priest was killed in the cream over the Adda. Evidence on these phenomena are too numerous, hundreds and thousands of people were their witnesses, the whole country worried and anxious, doubting reality of these meteorites can not be confusing, especially since it seems surprising that in the last century, almost all scientists reject the validity of these reports, looking at them, as to the consequences of superstition, deception and deep confusion, and a fall of stones from the sky was considered physically impossible. When in 1790 was published on the above-mentioned Zagreb meteorite Shtyutts said: "Only those who are quite ignorant of natural science, may believe that stones fall from the sky. In 1751 this had convinced even scientists in Germany, but then reigned complete ignorance of science and of physics in our time is inexcusable assume any probability of such tales. " In 1790, at Zhyulyaka in Gascony fallen meteorite, the authorities of the area regarded the phenomenon with commendable prudence: a protocol was signed by 300 witnesses. But when that document is presented to the Paris Academy, then officially confirmed the news, it felt just stupid.

TEMPERATURE in the mines. GEOMETRIC DEGREES

How different are the results obtained at different times, show Beknalya coal mines in England: the temperature of coal at the time of exposure was 22 °, but ten months later, 15 ° C. The thermometer should invest as deeply as possible into the borehole to be drilled perpendicular to the surface of the rock, so drilling tsak develops heat, you have to wait until the hole has cooled again, and then carefully to protect the thermometer from the influence of the air. So you can watch if not entirely accurate temperature, then at least close to true. Numbers obtained in this way, find a lot of hesitation, but if you ignore those irregularities, very special is the distribution of heat in the famous copper mines in the Upper Lake in North America. Enormous accumulations of water, holding in its deepest parts of the temperature at 4 ° C, are cooling properly; like cold compresses, they absorb heat and lower the temperature of the mines: the closer to the lake are the last, the slower the temperature rise in them. Typically, geothermal degrees for GF mean = 16? 5 m in the same Ostseola mine, located 8 km from the lake, it rises to 23.3 meters and the mines that lie even closer - up to 30,5 m and even to 37,2 m. According to Wheeler (Wheeler), the cooling effect of water has already discreetly at a distance of 12 - 13 miles. Rich material for observations represent artesian wells: they enable us to determine the temperature, which has water at a certain depth. Compared with the mines of the wells are characterized by more accurate and more rapid rise in temperature with depth.

The temperature of the earth's crust

For the purpose of obtaining coal and metal mines every year deeper and larger and larger areas of the mountain cut through tunnels - there is the question: Where lies the boundary beyond which human labor is not possible due to high temperatures? The world's richest deposits of gold and silver is Kompstokskaya lived in Nevada, on the border of California. In the period from 1860 to 1876 there produced silver at 237 million dollars. But, despite the fabulous riches of the mine fear that further development it will soon be impossible: a terrible fire in some places, making miners work extremely hard. The workers are in the temperature from 42.2 to 46,7 °; if it and take a man here, only because the mine air is very dry, and sometimes come across colder areas, in the hottest parts of the mine worker is unable to continue their work more 10 minutes. Attempts were made to mine and where the temperature reaches 50 °, but all too soon it turned out to be unenforceable: mental illness and rapid death were the consequence of such a bold move. However, and now the death rate among miners, an unusually large: the love of money dooms many victims to perish in these steamy pits. However, in the mines Kompstokskoy core reason for the high temperature is not as much depth as local adverse conditions, such as, for example. The existence of hot springs: in the same deep mines pribramskih dominates the relatively mild temperatures. As the temperature increases with the depth necessary to be considered also for other mining operations.

The rise in temperature with depth

That explanation is now accepted by almost all geologists: community events, and high temperature of the internal parts of the Earth, which is proved by volcanoes, are decisive arguments in favor of this view. As for other explanations, none of them can be considered as satisfactory. We do not know of any chemical process, which would have been so common on Earth and would have occurred with such intensity that it can be attributed to an increase in temperature with depth and the melting of large masses of igneous rocks. The same must be said about the transformation of mechanical work into heat. You can probably point to the orogenic processes, but in this case would have been zamechaemy significant differences between the geothermal features of the newest mountain ranges, what are the Alps and the plains, where these processes have not acted. In fact, this is not observed, yes, finally, and this source would be insufficient for the formation of such huge amounts of heat. With regard to the hypothesis that the passage of the Earth and the entire solar system through the warmer regions of the world community, it is unlikely, and you can look for the causes of the phenomenon. But this hypothesis, we will not parse: it now has almost no supporters. Tried to prove that the change of geothermal degrees with depth does not match the fact of the gradual cooling of the Earth from a molten state. To more clearly imagine it, we turn to the properties of the heated and cooling mass. The main issue here is whether the increase geothermal degrees toward the center, or decrease, ie, whether the slower growth in the depths of warmth, or accelerated, and if we find on the surface of the geothermal degrees 33 m, then will it be at a greater depth 34 m, etc.

The average value of temperature rise

On the other hand, two different methods of research - definition of water temperatures in deep boreholes and the temperature of rocks in mines and tunnels - lead to different results. The reasons for differences in the numbers are very diverse: coal mines due to take place in their chemical oxidation processes have a relatively high temperature, the same can be said about those mines, which contain metals are easily destroyed by sulfur (pyrite). In addition, metals are good conductors of heat, can carry it from the deeper parts of the crust. Keys, beating with a considerable depth, brings with it heat, water is penetrating the surface and promotes cooling. According to Gyuyssena, the temperature affects the thermal conductivity of not only those species which are located below, but also those that lie at the top. Degree increase in temperature with depth is also dependent on surface properties. In the high mountains, with a relatively small mass, cooling is rapid, and because the geothermal degree here is great. Otherwise there is at the bottom of various vodovmestilisch: In general, the temperature at the bottom of deep lakes reaches only 4 °, and in the sea, it descends even lower, so the temperature increase under such waters should be very fast. In view of these conditions solution to the issue presents a series of insurmountable difficulties. Since the observation in boreholes provide a more permanent figure than the observation in the mines and the mines, then they mainly use and for further findings; calculated from this average geothermal degrees = 33 m, take that number and correspond to generally raise the temperature of the Earth depth.

DEEP DRILLING WELLS AND TEMPERATURE

Observations, especially to enrich science, were made in deep boreholes and long tunnels. In Shperenberga, 42 km south of Berlin, on the shore of a small lake Krummenskogo stands among high plains of gypsum hill 26.7 m in the plains of northern Germany gypsum is often accompanied by rock salt. Because of this it was decided to produce a Shperenberga drilling, and in 1867 work began on the site neglected plaster lomok; borehole passed first through a layer of gravel capacity 0,63 m, and then gypsum and anhydrite capacity 88.18 m occur on clean rock salt, cutting through this layer over the 1182.64 m in depth, borehole has not passed its entire water column and did not reach the rocks underlying the salt. The existence of vast salt resources could be proved under less deep drilling, but in view of the scientific value of an enterprise is particularly desirable to achieve a significant depth. In September 1871 work was interrupted at a depth of 1,272 m. The new drill soon left far behind Shperenbergskuyu borehole: in the literature of Altona have achieved the depth of 1338 meters with a temperature of 35,07 °, and in Shladebahe have Dyurrenberga - 1748.40 m. The latter passed through the Bunter Sandstone, Zechstein, dead red Lejeune, coal formation, and reached the upper tiers of the Devonian system. At different depths and Shperenbergskoy Shladebahskoy boreholes Dunker makes measurements, characterized by the utmost care. Errors were included and excluded the possibility: with the help of rubber, and Shladebahe with the clay, insulated top and bottom of a particular column of water whose temperature and measured: thus, the thermometer was protected from the influence of the currents coming from the upper and lower parts of the borehole.

Crystalline lava

Repeatedly pointed to the volatility of the chemical composition of lavas, with mean trahitovye and basaltic volcanic rocks. In fact, under the name of the lava we mean not any particular chemical and mineralogical on rock: the word denotes all the molten mass ejected by the volcano. "Everything that flows from the crater and deposited in new places, is called lava," - says Leopold von Buch. The number of species belonging to the category of lava, is rather limited: it is mainly trachytes, basalts and rocks, which occupy an intermediate position between them. In addition, there also may include some other breeds, characterized by the content of known minerals: leucite, nozeana, nepheline, etc. trachytes and basalts represent a difference not only in their chemical and mineralogical composition, lava flows, formed by them, have not the same physical properties . Basaltic lavas are inclined to spread in width and flow to the enormous extent; trahitovye lavas have a high density, lower mobility. Both ancient and modern basaltic lavas occur most often in the form of cover. The above-mentioned huge stream of scan-General of-iokula in Iceland belongs to the basalts. Generally in any volcanic area, you can find a number of examples to prove the validity of the above. On the contrary, trachytes represent short and wide streams with surface covered by numerous irregularities.

The relief of the moon

State of Emergency similarity ring Mountains of the Moon and terrestrial volcanoes can be seen in Fig. 122 and 123 and the second represents a fraction of the lunar surface, the first - the neighborhood of Naples, with Vesuvius and the Somme, with countless craters Flegreyskih fields, an astronomer, Monte Nuova Solfatara and lakes Avern-sky and Lukrinskim etc. This area is shown as it have had an observer on another planet if Earth was devoid of atmosphere. Another significant similarity between the annular lunar mountains with wide open craters on basaltic volcanoes. Hawaii in the Pacific. The value of lunar craters vary, from large rings with a diameter of 12 or more miles there are a number of transitions to the small volcanoes, barely visible at high magnification. Number of ring of mountains that are visible on the reverse side of the moon to us, in Schmidt, extends to 35,000, but the improvement of telescopes, I thought this great, now deceased expert on the Moon, their number will increase, at least, to 100,000. On some mountains, such as, from the mountains of Copernicus, Kepler, Tycho Brahe, radial divergent light stripes. This is not a hill and lowland. The origin of the bands due to the ability of some sort of lunar plateau strongly reflect the sun's rays. Formed such plateau simultaneously with the ring off. Series of hills, similar to our mountain ranges, observed on the moon in a smaller number, most significant of the mix is ??called the Apennines, and has some very high peaks.

Vesuvius

On the European continent there are now only one active volcano - Vesuvius. In addition, there is some news about eruptions in historical times Flegreyskih fields and Mefany in Greece. Among the burning mountains Vesuvius particularly attracts travelers and well-studied, since together with Flegreyskimi fields he satisfactorily explains most of the phenomena, then we'll start with him and our familiarity with volcanoes. Who has seen the neighborhood of Naples, he could not pay attention to the contrasts between the separate parts of the bay, they create those kinds of charming, which is famous for this area. If the part of Naples, with that part of the coast, where lies the aquarium, look at the sea, the distance be presented chain of high jagged mountains, formed by light limestone and outliers among the entire area; it - chain Monte Angelo (the ancient Mons Lactarius); it begins in the vicinity of Salerno and Amalfi, down the slopes of Castellammare and Sorrento, and ends at the Cape of Minerva (Punta Campanella case) the continuation of the chain is already the island of Capri. This series of limestone hills of Cretaceous system limits the bay from the south-east and a spur of the Apennines, it is formed by ancient marine sediments, and has nothing to do with the volcanic phenomena. Sarno river system with its large tributaries separates chain Monte Angelo from Vesuvius, the majestic cone of its semi-circle and the Somme sharply distinguished by their dark masses among environmental change, they can serve as an excellent example of the volcano, active for a long time, and present a striking contrast to the long chain Monte Angelo .

Somma and Mount Vesuvius

We present here a few figures illustrate how the height of Mount Vesuvius: 1749 1160 m February 1846:1193 1847:1240 m m August 1810 1249 "March 1846:1196" 1850-1291 "1822 1269" July 1846:1219 "1855:1286" 1832 1140 "January 1847:1222" 1855:1234 "1845 1182" March 1847:1237 '1868:1297' After measuring, produced in 1822, there was a strong eruption, the upper part of the cone collapsed, and Vesuvius on par with Somme. Thereafter, as shown by measurements of Amati, made over forty years, Vesuvius is gradually growing. Eruption in 1855 lowered it to 60 meters, then the cone again went narostat and in 1868 reached a great height. During the disaster struck again in 1872 newly-vertex. Thus, during the time when the measurements, the cone of Vesuvius exceeded the Somme, where the height of 1,110 m, but sometimes, for example. during eruptions in 1631 and the second in 1737, collapsed a huge part of Mount Vesuvius, which he did following the Somme. Since the destruction of Pompeii to the XVII century. There were eight eruptions, separated by long periods of complete rest. It is noteworthy that during breaks erupts Flegreyskih neighboring fields and Ischia island: in 1198 acted Solfatara from Pozzuoli, in 1302 Monte Epomeo on Ischia. In 1538 abundant volcanic rocks and ash from Pozzuoli erected a cone of Monte Nuovo, in 1139 till the 1631 Vesuvius was inactive, and only in 1500 to a low degree spewed ash. Eruption of Vesuvius occurred in 203, 472, 512, 685, 993, 1036, 1139 and 1500-m years.

The theory of lifting

Some proponents of the theory does not attributed any significant role accumulation and explained the origin of volcanic mountains lift, while others, eg. Humboldt in his "Cosmos", did not share such extreme views and the possibility of formation of the cones by a single accumulation. Not to mention the particulars, are difficult to explain lift, enough to indicate that, in direct contradiction to the parsing theory is the following fact: almost all ring shafts consist exclusively of volcanic rocks, whereas in the formation of the crater uplift could participate limestones, shales, sandstones to the same extent as lavas and tuffs. This caused the followers of the theory to assume that in the first period of cooling of the earth, when there were no mountains, primeval crust covered with cracks through which resulted basalts, trachytes, and others related to them breed in the form of large sheets. The latter were raised by the volcanic crater and the burning mountains. But this assumption only explains the presence of volcanic rocks in the crater, but not limited to their predominance, in any case, would have to exist a sharp boundary between the initial components of a raised ring and the latest volcanic products, but how wonderful it proved Gartun, this boundary is actually does not exist. The best argument in favor of the theory of lifting felt inclined position of many lava sheets and beds, as well as the steepness of some volcanic cones, exceeding the natural angle of granular materials, special emphasis was placed heavily tilted lava flows, since it was assumed that the liquid magma can not resist and harden on the steep slopes.

Isle of Lipari and Volkan

Only the abundance of hot springs that contain hydrogen sulfide, is a remnant of the old volcanic activity. Pays special attention to broad development are rich in silica trahitovyh lavas. This group of rocks called the Roth and liparite. Along with powerful streams of glassy obsidian found on Lipari and grainy trachytes. Especially the enormous growth reaches here pumice. This glassy, ??but very porous rock that resembles a sponge or thick foam, riddled with numerous voids and has a gray, much less black. Pumice in Europe, as well as most of the other volcanoes is rich in silica volcanic glass. On the islands of the southern seas as Cohen observed and rich in silica glass puzyristye so-called basaltic pumice. Due to numerous air voids pumice floating on the water, but the way, until, until all the air expelled. Not surprisingly, this volcanic product is carried away by sea currents and wind away from their place of education and deposited in remote areas. After a large eruption Konzegvina in Nicaragua, the ship ran Conway at 7 ° 26 '. sh. and 104 ° 45 'west. debt, from Greenwich to the great masses of floating pumice, at a distance of 1100 English miles from the eruption of the ship met with a broad band of pumice that covered the sea for 40 miles. This wonderful breed, found mainly among the loose product of many volcanoes, rare in lava flows found on Lipari in large numbers and takes a prominent part in the structure of the island. Almost all of that pumice, which refers to European trade, thrown eruptions near Cape Bianco on Lipari.

The lava flow of Vesuvius

Below Foss della Vetrana flow again divided, one up his sleeve rushed to Mass. and San Sebastiano and partially destroyed these towns, the other went to the San Dzhordzho and Kre-mano, but did not reach him. It was curious to watch the monastery, was moving among the gardens, tree, catch it, flickering up and burned. From the main crater rose a huge cloud, at first it was very white and consisted of pure water vapor, but gradually grew darker and darker: the huge mass of finely divided material flew with him. In Naples, the ash began to fall and soon fell asleep cone of Vesuvius: mountain climbing has become difficult due to its flowability of new slopes. Eruption in 1872 remarkable in two respects: a terrible explosion of volcanic activity emerged almost overnight, but soon calmed down, after 24 hours after the crash lava stopped translate into atrio, the clouds dissipated, ash rain stopped. Despite the short duration of the eruption, the mountain has undergone significant changes, they studied quite accurately, thanks to a fluke. Swiss geologist Professor. Game of Zurich, made accurate drawings of Mount Vesuvius in a few days before the accident; after the eruption, he made shots from the same places. From the Naples summit seemed so long equally rounded on all sides, and now it has been cut obliquely mentioned above Bocca on the outer side has disappeared from the atrio was visible crack formed during the night of 25 th (for photographs Sommer) on April 26 ziyavshaya in the form of a deep precipice, the edge of the crater at a considerable distance collapsed and the crater itself has expanded.

Volcanic bombs

Frequently crashes down in a crater larger or smaller part of the old cone and crush again thrown up: sometimes, all the old cone flies into the air. But the wreckage of the cone gives only a small portion spewed friable products: the main mass of them consists of molten rock that are ejected from deep and powerful burst of steam grinding into fine dust, like water, which is fired from a pistol. The validity of this view confirmed by many phenomena, and above all a special type of round or oval so-called "twisted bombs." In Naples, they are called "tears of Vesuvius, is chunks of lava ejected from a crater in the molten state and solidified during flight through the air, due to rotational motion, they were covered with spiral grooves. In most cases, loose products superior to the mass of flowing lava. If the eruption occurs under water or solids to fall into the sea, formed laminated sediments of volcanic tuff, sometimes enclosing the remains of marine animals. All the Neapolitan campaign consists of rocks, their origin can hardly be attributed to the activity of Vesuvius; probably admit that they are cast out by volcanoes Flegreyskih fields. According to Tseekke them should be attributed to eruptions of Crater Camaldoli.

The first travelers-openers

Remains a testimony to that already in ancient times people crossed the ocean. It is true that time is not brought us reliable information about these great feats. After all, important maritime and trade routes were considered an important state secret, and carefully preserved. These rare images on a parchment-prototype for future cards - were destroyed, especially during wars. Approximately to 600 the year before Christ is one of the remarkable journeys of antiquity - the first sailing trip around Africa, which at that time was known as Libya. The ancient Greek historian Herodotus, who himself was a great explorer, wrote about the event this way: "We know that Libya is on all sides surrounded by sea, except where it borders with Asia. This discovery made the Pharaoh Necho. He fitted out a ship with the Phoenicians, who were supposed to get under sail until the Pillars of Hercules (Straits of Gibraltar) and back into the Mediterranean Sea. The Phoenicians came from the Red Sea into the Indian Ocean. When autumn came, they made a stop and landed on the shore. They sowed the seed and waited for the harvest. Harvested, drive again set sail. Meanwhile, passed for two years. It was only the third year they managed to swim to the Pillars of Hercules, to complete the journey and return home. They were told that during a voyage around Libya saw the sun on the right side, that maybe someone will seem plausible, but I believe it can not. " Something that could not believe the "father of history" Herodotus, for us now is the most reliable historical and geographical evidence.

Greek Pytheas journey to northern Europe

The world-famous epics of Homer's "Odyssey" contains many detailed instructions to mariners, and, of course, is based on real evidence of Greek sailors. By the year 800 BC they were already perfectly oriented to the Mediterranean, mastered it and started a more than 100 colonies. Around the time when Alexander of Macedon marched to campaign against the Persians came to India, the Greek navigator and astronomer Pea Fairy went to the Norwegian coast. Discoveries which he made in the North Sea, were the result of an unexpected deviation from the route. When he came into port Massalia (menny modern Marseilles), Greek merchants have agreed to Pytheas, that he would try to find a direct trade route to the "tin islands" at the southwestern tip of Britain, bypassing the Lands End, a lively center of trade in intermediate (then Cornwall) . Pytheas agreed and went north Gal Lee (modern France). Soon he was off the coast of Britain. And from there sailed further along the west coast of modern England, and came to Ireland. Then he went to the Hebrides and Orkney Islands, has not yet rounded the UK, which is mapped as a triangle. But he is slightly deviated to the north and probably went to the coast of Norway near Trondheim, and visited the island of Helgoland, famous for its amber. On the voyage Pytheas of antiquity were preserved only fragmentary information. Very often ridiculed his contemporaries and later writers, Pytheas called a liar and a fantasist. Why, you ask?

Observations of Vesuvius

From the vapors are allocated minerals, such as: hematite, copper chloride, etc., they cover rocks colorful bloom or fine crystals. At times, volcanic activity increases, opening up new holes, the allocation of the vapor increases, thrown stones and ashes, and there are even small lava flows. At this time and built up the crater due to the gradual accumulation of volcanic products. In one of these periods, it is from 1840 to 1850-ies., Scacchi produced observations of Vesuvius. We reported here a brief summary of the past few months, it is - the best way to present a picture of a mountain in the period in its activities. We followed a continuous volcanic activity for about two years. Almost all of the time it was restricted to the inner parts of the crater, and only on the last day, November 4, 1844, a strong lava flow has resurfaced. A lot of arguing about whether there is fire during eruptions. According to the old reports, he plays a big role, and especially clearly visible at night. Subsequently, however, were convinced that the phenomena are ascribed to the flame before actually occur due to reflection of the current lava, she illuminates a pair of clouds and produces the impression that the mountain of fire flies. But although a large scale phenomena of flame and are not observed, but in some cases, they are certain. A number of credible evidence indicates that out of the crater of the lava flows and from fumaroles release flammable gases; they and can form a flame, according to Siemens, is the ignition of flammable gases, especially hydrogen, plays an important role in the explosions.

The shape of the earth and its surface

However, the Earth actually takes the form not of an apple or a ball. It's more of a huge pumpkin: a ball, flattened on two sides. Protruding ribs and flattened make Earth look like a rugby ball. But the geography of the earth is called the geoid (n - Earth, eidos - form). And it is because our planet has a specific shape, which is difficult to convey in comparison. Although one can often hear this: the planet Earth is in the form of an ellipse. But it should be remembered here that any comparison with respect Well, what is the Earth's surface? And what did she like? If we had climbed high above the ground and looked out upon its surface, we would see that most of it covered with water. Much smaller areas are free of water. These sites are called the dry land. Land of the globe consists of continents and islands, mainland - it is a large land mass the earth's surface above the level of the ocean. According to its geological origin differ in six continents. Sometimes they are called continents. It Eurasia, Africa, North America, South America, Australia and Antarctica. But earlier, when people did not know the exact number of continents, and only started to take the first steps in the discovery, each new land they called part of the world. Therefore, some have survived and even the names of the continents on the parts of the world: Europe, Asia, Africa, America (but originally a long time it was known as the West Indies because Columbus discovered it, I thought that sailed to India) Australia Oceania.

Spring agricultural chores

Many days there is not the sun, and the entire northern half of the land comes the shortest night. Days June 21 and 22 are the longest of the year. Night at the numbers at the latitude of Moscow continues all the 6 o'clock or 25 minutes a day or 17 hours 35 minutes. In this case, in fact light of the day even longer. It extended through a long and bright Dawn. After June 22 the sun each day rises later and sets earlier than the day before. Despite the loss of the day, it continues with the excess heat the earth, and next month is usually warmer than June. Day of the highest position of the sun at noon considered the beginning of astronomical summer quarter. Biological early summer, we believe, from the time when apple trees bloom in the gardens. On average, this coincides with the flowering of red clover. First period - from late flowering apple trees to flowering limes. On average, this period lasts from early June to mid July. Second period - from small-leaved lime trees blooming until the first frost in the soil. Average date of first flowering of small-leaved lime tree falls on July 10-13, and the average time the first frost on the soil surface, on September 14. This second period, naturally, falls into two halves, characterized primarily by their meteorological characteristics. The first half is the most warm season of the year when, despite the start of the reduction of the day, the degree of heating of the soil and water is kept still above the average temperature of the first year period.

Nil

Source of the Nile River Boats think. The river originates at an altitude of 2000 meters on one of the arrays in East Africa and flows into Lake Victoria. From the lake it flows under the name of the Victoria Nile flows through Lake KIOGE and empties into Lake Albert, below which was named the Albert Nile. On all this over the river is mountainous in nature, for it has many rapids, waterfalls, why are formed. The biggest of them - Murchison Falls, which reaches a height of 40 meters. Upon leaving the Nile from the highlands to the plains, the waters slow down for. Here he is known by its Arabic name of Bahr al-Jabal, which means "River of Mountains". The largest tributaries of the Nile at this point - the river Bahr el-Ghazal and the Sobat. Below Co-baht river was named the White Nile. And in Ethiopia, the White Nile merges with the Blue Nile, which originates from the Ethiopian highlands, flowing from Lake Tana. Now the river is obtained the name by which she is known around the world .- Neil. It is the only African rivers that flows into the Mediterranean Sea and is the source of life in the arid deserts on both sides of its flow. Since ancient times, the Nile is the lifeblood of the people who settled along its shores. It is with its beaches due to the emergence of human history and existence of Egyptian civilization. It is therefore not surprising that the river god of the ancient inhabitants of the valley. Then it was believed that the Nile - the border between Asia and Africa.