Elements of Surveying, and Navigation: With Descriptions of the Instruments and the Necessary TablesA. S. Barnes & Company, 1854 - 322 páginas |
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Página 76
... reading of the instrument , for any position of the vernier , expresses the distance from the point where the graduation on the limb begins , marked 0 , to the 0 point of the vernier . In the diagram , that distance is ex- pressed by ...
... reading of the instrument , for any position of the vernier , expresses the distance from the point where the graduation on the limb begins , marked 0 , to the 0 point of the vernier . In the diagram , that distance is ex- pressed by ...
Página 77
... reading an instrument which has a vernier . Read the limb in the direction of the graduation up to the division line next preceding the 0 point of the vernier ; this is called the reading on the limb . Look along the vernier till a ...
... reading an instrument which has a vernier . Read the limb in the direction of the graduation up to the division line next preceding the 0 point of the vernier ; this is called the reading on the limb . Look along the vernier till a ...
Página 78
... readings will be the true angle , unless the 0 point of the vernier shall have passed the 0 point of the limb , in which case the greater reading must be subtracted from 360 ° , and the remainder added to the less . TO MEASURE A ...
... readings will be the true angle , unless the 0 point of the vernier shall have passed the 0 point of the limb , in which case the greater reading must be subtracted from 360 ° , and the remainder added to the less . TO MEASURE A ...
Página 79
... readings , may be obtained by subtracting half their difference from the first reading . If the first reading is less than the second , the half differ- ence must be added to the first . Hence , To find the index error , take the reading ...
... readings , may be obtained by subtracting half their difference from the first reading . If the first reading is less than the second , the half differ- ence must be added to the first . Hence , To find the index error , take the reading ...
Página 99
... reading . SURVEYING WITH THE COMPASS . 2. The line about which the earth revolves is called its axis ; and the two points in which the axis meets the sur- face of the earth , are called the poles . plane , and its intersection with the ...
... reading . SURVEYING WITH THE COMPASS . 2. The line about which the earth revolves is called its axis ; and the two points in which the axis meets the sur- face of the earth , are called the poles . plane , and its intersection with the ...
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Términos y frases comunes
axis back-sight base line bearing called centre column comp Cosine Cosine D 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 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 Sine Cotang Sine D 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 14 - The logarithm of the quotient of two numbers is equal to the logarithm of the dividend minus the logarithm of the divisor.
Página 42 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees...
Página 13 - The logarithm of a number is the exponent of the power to which it is necessary to raise a fixed number, in order to produce the first number.
Página 25 - ... 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 bounding lines in the same direction, the first side of the one is equal to the first side of the other, the second to the second, the third to the third, and so on. 22. Two polygons are mutually equiangular, when...
Página 20 - The difference of the logarithms, as here used, means the algebraic difference ; so that, if the logarithm of the divisor have a negative characteristic, its sign must be changed to positive, after diminishing it by the unit, if any, carried in the subtraction from the decimal part of the logarithm.
Página 135 - Soon after the organization of the present government, several of the states ceded to the United States large tracts of wild land, and these together with the lands since acquired by treaty and purchase, constitute what is called the public lands or public domain. Previous to the year 1802 these lands were parcelled out without reference to any general plan, in consequence of which the titles often conflicted with each other, and in many cases, several grants .covered the same premises. In the year...
Página 96 - Then, find the areas of the triangles separately, and their sum will be the area of the quadrilateral.
Página 43 - The tangent of an arc is the line which touches it at one extremity, and is limited by a line drawn through the other extremity and the centre of the circle. Thus, AC is the tangent of the arc AB.
Página 28 - B + 0, the product would be indicated thus; (A+D)x(A-B+C), whatever is enclosed within the curved lines, being considered as a single quantity. The same thing may also be indicated by a bar : thus, A+B+OXD, denotes that the sum of A, B and C, is to be multiplied by D.
Página 1 - 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.