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. The same should be true of other methods used for finding the weight of the Earth and is based on determining the number of oscillations of the pendulum in the high mountains and deep mines, and in this way was impossible to get accurate results. Of all the methods proposed so far, the most successful one that has been applied first to Cavendish, and then bailie, roots, and Reich. They took a smooth wooden block, and at the ends of reinforced identical balls, bar was hung on a thread in a horizontal position. After that, to the balls podnosili pieces of lead. Because of their severity, they attracted the balls stick out of balance, and the thread on which it hung, spinning. Weight of lead pieces were known, the value of their attractive force could be calculated; exactly known, the force with which the Earth attracts the balls: this force is expressed by their weight. For all these data it was possible to find the mass of Earth. The experimental results do not differ; Cornu, carried out the study after their all with sophisticated instruments found that the density of Earth is 5.56, this number is usually accepted by all. Recently, Jolly Payntine in Munich and Manchester began to determine the mass of the Earth with the help of the scales: they measured the increase in weight of the scales, beneath which lies a lead ball; Payntin found in this way that the density of Earth = 5.69, and Jolly - 5.692. Uilson proposed a new method: it studied the effect of attracting masses on the pendulum. For the experiments, he took a cast-iron cylinders, each weighing 325 kg. This seems very accurate, gave way to the density of Earth's figure 5.59, the most recent Shternek got 5,7 and Garknes - 5,58.