Elements of Surveying and Navigation: With Descriptions of the Instruments and the Necessary TablesA.S. Barnes & Company, 1852 - 392 páginas |
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Página 32
... feet , to a scale of twenty feet to the inch . Take one inch from the scale of inches : then place one foot of the dividers at the twentieth division , and open the sector until the dividers will just reach the twen- tieth division on ...
... feet , to a scale of twenty feet to the inch . Take one inch from the scale of inches : then place one foot of the dividers at the twentieth division , and open the sector until the dividers will just reach the twen- tieth division on ...
Página 34
... feet to the inch . The length of the line 75 feet , being divided by 25 , will give 3 , the number of inches which will represent the line on paper . Therefore , draw the indefinite line AB , on which lay 4 C B off a distance AC equal ...
... feet to the inch . The length of the line 75 feet , being divided by 25 , will give 3 , the number of inches which will represent the line on paper . Therefore , draw the indefinite line AB , on which lay 4 C B off a distance AC equal ...
Página 35
... feet is to be laid down on paper , on a scale of 40 feet to the inch ; what length must be taken from the scale ? 40 ) 640 ( 16 inches . 2. If a line of 357 feet is to be laid down on a scale of 68 feet to the unit of the scale ...
... feet is to be laid down on paper , on a scale of 40 feet to the inch ; what length must be taken from the scale ? 40 ) 640 ( 16 inches . 2. If a line of 357 feet is to be laid down on a scale of 68 feet to the unit of the scale ...
Página 36
... feet , and 120 feet , be the given sides ; and A = 30 degrees , the given angle : to de- scribe the triangle on a scale of 200 feet to the inch . Draw the indefinite line DG , and at the point D , make the angle GDH equal to 30 degrees ...
... feet , and 120 feet , be the given sides ; and A = 30 degrees , the given angle : to de- scribe the triangle on a scale of 200 feet to the inch . Draw the indefinite line DG , and at the point D , make the angle GDH equal to 30 degrees ...
Página 61
... feet in height , the angles of depres sion are measured from the top of the tower , and are found to be , of the nearer 57 ° , of the more remote 25 ° 30 ' : re- quired the distance between the objects . Ans . 173.656 feet . A 2. In ...
... feet in height , the angles of depres sion are measured from the top of the tower , and are found to be , of the nearer 57 ° , of the more remote 25 ° 30 ' : re- quired the distance between the objects . Ans . 173.656 feet . A 2. In ...
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Términos y frases comunes
axis back-sight base line bearing called centre column comp corresponding Cosine Cosine D Cotang course decimal degrees determined diff difference of latitude difference of level direction divided double meridian distance draw east error example feet figure fore-sight given angle given line given point half hence horizontal distance horizontal line horizontal plane hypothenuse inch instrument intersection LatDegDegDegDeg length limb line of collimation logarithm longitude M.
M. Sine marked measure method middle latitude miles multiplied paper parallel PARALLEL SAILING perpendicular plane of reference plane sailing plane triangle protractor quotient radius right angles right-angled triangle rods sailing scale of chords scale of equal screws secant sector sides sights spherical excess spider's lines square chains staff station straight line subtract surface survey Tang tangent telescope theodolite trigonometrical vernier plate vertical yards
Pasajes populares
Página 10 - The logarithm of . the quotient of two numbers, is equal to the logarithm of the dividend diminished by the logarithm of the divisor.
Página 38 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees...
Página 61 - Being, on a horizontal plane, and wanting to ascertain the height of a tower, standing on the top of an inaccessible hill, there were measured, the angle of elevation of the top of the hill 40°, and of the top of the tower 51° ; then measuring in a direct line 180 feet farther from the hill, the angle of elevation of the top of the tower was 33° 45' ; required the height of the tower.
Página 1 - O's, to catch the eye, and to indicate that from thence the two figures of the Logarithm to be taken from the second column, stand in the next line below. N. Log. N. Log. N. Log. N. Log. 1 2 3 4 5 o.
Página 21 - ... 20. An EQUILATERAL polygon is one which has all its sides equal ; an equiangular polygon, is one which has all . its angles equal. 21. Two polygons are mutually equilateral, when they have their sides equal each to each, and placed in the same order : that is to say, when following their...
Página 113 - Longitude of the preceding course^ plus the Departure of that course, plus the Departure of the course itself* The Double Longitude of the last course (as well as of the first) is equal to its Departure. Its "coming out" so, when obtained by the above rule, proves the accuracy of the calculation of all the preceding Double Longitudes.
Página 9 - THE LOGARITHM: of a number is the exponent of the power to which it is necessary to raise a fixed number, to produce the given number.
Página 17 - The minutes in the left-hand column of each page, increasing downwards, belong to the degrees at the top ; and those increasing upwards, in the right.hand column, belong to the degrees below.
Página 39 - The secant of an arc is the line drawn from the centre of the circle through one extremity of the arc, and limited by the tangent passing through the other extremity. Thus, . 00 is the secant of the arc AB.
Página 142 - Now, if the elongation, at the time of observation, was west, and the north end of the needle is on the west side of the line, the azimuth, plus the angle shown by the needle, is the true variation. But should the north end of the needle be found on the east side of the line, the elongation being west, the difference between the azimuth and the angle would show the variation, and the reverse when the elongation is east. 1. Elongation west, azimuth 2° 04' North end of the needle on the west, angle...