A Treatise of Practical Surveying: Which is Demonstrated from Its First Principles. Wherein Every Thing that is Useful and Curious in that Art, is Fully Considered and Explained
Lewis Nichols, 1806 - 452 páginas
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40 perches ABCD acres Answer Artificial Sines azimuth base bearing blank line centre chains and links chord circle circumferentor Co-sec Co-sine Co-tang Co-tang|Secant column contained cyphers decimal decimal fraction Dep Lat divided draw drawn east edge ExAMPLE feet field-book figures four-pole chains half the sum height hypothenuse inches instrument Lat Dep latitude logarithm measure meridian distance multiplied needle number of degrees off-sets ooooo parallel parallelogram perpendicular Plate prob PROBLEM protractor quotient radius right angles right line scale of equal SCHOLIUM secant second station sect semicircle side sights square root stationary distance sun's survey taken Tang tangent thence theo theodolite THEOREM trapezium triangle ABC trigonometry true amplitude two-pole chains vane variation whence
Página 25 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees ; and each degree into 60 equal parts, called minutes ; and each minute into 60 equal parts, called seconds ; and these into thirds, &c.
Página 40 - The angle in a semicircle is a right angle ; the angle in a segment greater than a semicircle is less than a right angle ; and the angle in a segment less than a semicircle is greater than a right angle.
Página 43 - Triangles upon equal bases, and between the same parallels, are equal to one another.
Página 103 - TO THEIR DIFFERENCE ; So IS THE TANGENT OF HALF THE SUM OF THE OPPOSITE ANGLES', To THE TANGENT OF HALF THEIR DIFFERENCE.
Página 31 - Figures which consist of more than four sides are called polygons ; if the sides are all equal to each other, they are called regular polygons. They sometimes are named from the number of. their sides, as a five-sided figure is called a pentagon, one of six sides a hexagon, &"c.
Página 31 - ... they are called regular polygons. They sometimes are named from the number of their sides, as a five-sided figure is called a pentagon, one of. six sides a hexagon, &c. but if their sides are not equal to each other, then they are called irregular polygons, as an irregular pentagon, hexagon, &c.
Página 45 - The hypothenuse of a right-angled triangle may be found by having the other two sides ; thus, the square root of the sum of the squares of the base and perpendicular, will be the hypothenuse. Cor. 2. Having the hypothenuse and one side given to find the other; the square root of the difference of the squares of the hypothenuse and given side will be the required side.
Página 265 - As the length of the whole line, Is to 57.3 Degrees,* So is the said distance, To the difference of Variation required. EXAMPLE. Suppose it be required to run a line which some years ago bore N. 45°.