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 25
... describe some of the simpler instruments and their uses . DIVIDERS . a 36. The dividers is the most simple and useful of the instruments used for drawing . It consists of two legs ba , bc , which may be easily turned around a joint at b ...
... describe some of the simpler instruments and their uses . DIVIDERS . a 36. The dividers is the most simple and useful of the instruments used for drawing . It consists of two legs ba , bc , which may be easily turned around a joint at b ...
Página 27
... describe the square abcd . the sides ab and de each into ten equal parts . and the other nine parallels as in the figure . Produce ba to the left , and lay off the unit of the 1 , 2 , 3 , & c . Then scale any convenient number of times ...
... describe the square abcd . the sides ab and de each into ten equal parts . and the other nine parallels as in the figure . Produce ba to the left , and lay off the unit of the 1 , 2 , 3 , & c . Then scale any convenient number of times ...
Página 29
... describe the arc BC . Then take from the scale the chord of the given angle , say 30 de- grees , and with this line as a radius , and B as a centre , describe an arc cutting BC in C. Through A and C SEMICIRCULAR PROTRACTOR . 30 10 S10 ...
... describe the arc BC . Then take from the scale the chord of the given angle , say 30 de- grees , and with this line as a radius , and B as a centre , describe an arc cutting BC in C. Through A and C SEMICIRCULAR PROTRACTOR . 30 10 S10 ...
Página 32
... describe two arcs intersecting each other in D : draw AD , and it will be the perpendicular required . II . From a given point without a straight line , to let fall a perpendicular on the line . From the point A as a centre , with a 49 ...
... describe two arcs intersecting each other in D : draw AD , and it will be the perpendicular required . II . From a given point without a straight line , to let fall a perpendicular on the line . From the point A as a centre , with a 49 ...
Página 33
... describe an arc cutting the line BD in the two points B and D : then mark a point E , equally dis- tant from the ... describe the arc IL , terminating in the two sides of the angle . From K the point A as a centre , with a distance AE ...
... describe an arc cutting the line BD in the two points B and D : then mark a point E , equally dis- tant from the ... describe the arc IL , terminating in the two sides of the angle . From K the point A as a centre , with a distance AE ...
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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...