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 ... The Whole Illustrated with CopperplatesP. Wogan, 1795 - 319 páginas |
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Página 154
... Set up your Inftrument at the Angular Point , and thence direct the Sights along each Leg of the Angle , and note down thier refpective Bearings as before ; the Difference of thefe Bearings , if lefs than 180 , will be the Quantity of ...
... Set up your Inftrument at the Angular Point , and thence direct the Sights along each Leg of the Angle , and note down thier refpective Bearings as before ; the Difference of thefe Bearings , if lefs than 180 , will be the Quantity of ...
Página 156
... Set up your Inftrument at B , unscrew it , and lay the Ends of your Index to 360 , and 180 ; turn the whole about with the 360 from you , or 180 next you , till you cut the Object at A ; fcrew the Inftrument faft , and direct your ...
... Set up your Inftrument at B , unscrew it , and lay the Ends of your Index to 360 , and 180 ; turn the whole about with the 360 from you , or 180 next you , till you cut the Object at A ; fcrew the Inftrument faft , and direct your ...
Página 157
... Set your Inftrument at the firft Station , and lay the Index to 360 and 180 , with the Flower - de - Luce of the Box next the 360 ; unscrew the Inftrument , and turn the whole about , till the North and South Points of the Needle cut ...
... Set your Inftrument at the firft Station , and lay the Index to 360 and 180 , with the Flower - de - Luce of the Box next the 360 ; unscrew the Inftrument , and turn the whole about , till the North and South Points of the Needle cut ...
Página 159
... set the South of the Index to the De- gree of the laft Station ; turn the whole about , with the South of the Index to you , and cut the Object at the foregoing Station ; fcrew the Inftrument fast , and with the North of the Index , to ...
... set the South of the Index to the De- gree of the laft Station ; turn the whole about , with the South of the Index to you , and cut the Object at the foregoing Station ; fcrew the Inftrument fast , and with the North of the Index , to ...
Página 163
... set on the three legged Staff . 1. To take the Angles of the Field by the Table . Having placed the Inftrument at the first Station , turn it about till the North End of the Needle be over the Meridian , or Flower - de - Luce of the Eox ...
... set on the three legged Staff . 1. To take the Angles of the Field by the Table . Having placed the Inftrument at the first Station , turn it about till the North End of the Needle be over the Meridian , or Flower - de - Luce of the Eox ...
Términos y frases comunes
40 Perches ABCD Acres alfo alſo Anſwer Area Bafe Baſe Bearing becauſe bifect blank Line Cafe Center Chains and Links Chord Circle Circumferentor Co-fine Column confequently Cyphers Decimal defcribe Departure Divifion draw drawn Eaft eaſily Eaſt faid fame fecond Field-Book Figures fince firft Meridian firft Station firſt fmall Squares Four-Pole Chains ftationary Line fuch given half the Sum Inch Index infert Inftrument Interfection laft laid Latitude lefs Logarithm Mearing Meaſure Meridian Diſtance multiplied muſt Needle North obferve Off-fets oppofite parallel Parallelogram Perches Perpendicular Piece of Ground Plate Point Prob Protraction Protractor Quotient Radius refpective right Angles right Line Scale of equal SCHOLIUM Secant Sect Semicircle ſhall Side Sine South Square Root Sun's Survey taken Tangent thefe Theo Theodolite theſe thofe thoſe thro Trapezium Triangle ABC Trigonometry Two-Pole Chains uſed Variation Weft whofe
Pasajes populares
Página 13 - The circumference of every circle is supposed to be divided into 360 equal parts, called degrees; and each degree into 60 minutes, each minute into 60 seconds, and so on.
Página 88 - C' (89) (90) (91) (92) (93) 112. In any plane triangle, the sum of any two sides is to their difference as the tangent of half the sum of the opposite angles is to the tangent of half their difference.
Página 56 - ... logarithm of that number. EXAMPLE. • Required, the logarithm of 365. Answer, 2.56229. And though most tables of logarithms run but to 10000, yet by them the log. of any number not exceeding 10,000,000 may be found, and on the contrary, the number to any such logarithm, thus : 1 Find the log. of the first four figures of the given number 2. Take that log. from the log: of the number next following, and note their difference, 3. Multiply that difference by the remaining figures of the given number...
Página 91 - In the triangle ABC, there is given AB 240, the angle A 46° 30', and BC 200, to find the angle C, being acute, the angle B, and the side AC.
Página 89 - ED. that is as the sum of the two sides AB and BC, is to their difference ; so is the tangent of half the sum of the two unknown angles A and C, to the tangent of half their difference.
Página 32 - KCML, the sum of the two parallelograms or square BCMH ; therefore the sum of the squares on AB and AC is equal to the square on BC.
Página 19 - Four quantities are said to be in proportion when the product of the extremes is equal to that of the means, thus if A multiplied by D, be equal to B multiplied by C, then A is said to be to B as C is to D. POSTULATES OR PETITIONS. 1 . That a right line may be drawn from any one given point to another. 2. That a right line may be produced or continued at pleasure. 3. That from any centre and with any radius, the circumference of a circle may be described.
Página 13 - A chord is a right line drawn from one end of an arc or arch (that is, any part of the circumference of a circle) to the other ; and is the measure of the arc. Thus the right line HG, is the measure of the arc HBG.
Página 72 - ... these three proportions, for DE we put its equal be, for AE put ab, and for AD put ac, they will become AB : ab : : AC : ас, and AB : ab : : BC : be, and AC : ac : : BC : be.
Página 285 - Then if the true and magnetic amplitudes, be both north or both south, their difference is the variation ; but if one be north and the other south, their sum is the variation ; and to know whether it be easterly or westerly, suppose the observer looking...