First of all, keeping it on the board tablet, the fingers close line of sight. Clarifying the position of the ruler, it has to move several times. The line is unstable, especially in windy weather, often shifting from the dowry to her position; hold the line on its base is only possible when the plate is positioned horizontally, which is not always possible to achieve. Sight is the line passes through the vertex angle of 60 °. For the exact same pickup lines on objects better if this line passes through the top of a sharp angle. If you hover on the line items side semicircular recess for holding and moving lines distract the observer's eye. Sharp edge lines wear out quickly, jag, why draw a line on them obtain rough. Our proposed design sight lines devoid of these shortcomings, is simple in design and easy to operate. It consists of two lines - the flat and secured to the line having a cross-sectional shape of a right triangle (Fig. 1). Line can be made of conventional flat wooden ruler to attach the trihedral prism of solid wood (beech, oak). On the beveled and flat part of the division line marked the decimal scale. On the beveled side of the division are necessary for measuring and laying intervals, and the flat-used in the graphic works. Can cause division and the vertical side - for use with shelving distances. The length of the line of 205 mm, width at base 30 mm, the height of the vertical part of 15 mm. When shooting line on the tablet held by the thumb and forefinger of his left hand behind the horizontal platform. Line held his right hand, while not necessarily maintain the position of the ruler in the horizontal plane. Line of sight in this case passes through the vertex of the angle C is 45 °, which allows you to accurately direct line to the objects, even if they have a slight size or mild external signs. Shoot with the line is as follows. Depending on the area of ??rented land and the size of the tablet selected scale. Suppose we have chosen the scale of 1:10 000, ie, 1 cm - 100 m. At the plate, he is drawn down. Typically, measurement of distances on the ground with ocular estimation is the steps or in pairs of steps. To avoid the transfer of the number of steps to meters, count and build scale steps. It is a transitional, work, scale and built for the convenience of the tablet. At the plate scale steps lay the distance in paces, and on the metric-? whom the distance scale on the plan can be measured in meters. In this case, no special interpretations do not need it. To calculate the scale steps on the flat terrain was measured interval length of 100 m. Then the calm rhythmic step go the distance three times. Determine the average number of steps, falling to 100 m, for example, it is equal to 62 pairs of steps. Then in the adopted scale of 1 cm = 100 m = 62 pairs of steps is easy to find base-scale steps: 1 cm-62 pair of steps x cm 100 pairs of steps = 100:62 = 1.6 cm-scale steps, the base is drawn at plate below the metric scale. Before you start shooting tablet orient the compass and using sight lines to endorse items on the sharp edge of a ruler. Draw a line on the bottom right-hand line and knowing the distance to the object in steps, apply line beveled edge to the scale steps. Remember the proper length of the segment, lay it on the incised lines. Then endorse to other objects, and draws a line in the same way lay the distance, marking the common signs local objects. Reconstructed alidad allows for comparison with the triangular more accurately and quickly produce ocular estimation terrain
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