A Treatise of Practical Surveying, ...1808 - 440 páginas |
Dentro del libro
Página 107
... edge of its arc : by looking along its edge AC , to the top of the object whose height is re- quired ; and holding it perpendicular , so that the plummet may neither swing from it , nor lie on it ; the degree then cut by the hair , or ...
... edge of its arc : by looking along its edge AC , to the top of the object whose height is re- quired ; and holding it perpendicular , so that the plummet may neither swing from it , nor lie on it ; the degree then cut by the hair , or ...
Página 108
... edge AC , with small circular holes in them ; which are useful in taking the sun's altitude , requi- site to be known in many astronomical cases ; this is effected by letting the sun's ray , which passes thro ' the upper sight , fall ...
... edge AC , with small circular holes in them ; which are useful in taking the sun's altitude , requi- site to be known in many astronomical cases ; this is effected by letting the sun's ray , which passes thro ' the upper sight , fall ...
Página 161
... edge , and is in the mid- dle between the two ends . To this centre hole on the other side of the frame , there are the divi- sions of a semicircle , or 180 degrees ; and these again are subdivided into halves , or quarters , as the ...
... edge , and is in the mid- dle between the two ends . To this centre hole on the other side of the frame , there are the divi- sions of a semicircle , or 180 degrees ; and these again are subdivided into halves , or quarters , as the ...
Página 162
... edge of the index , so as through the sights ' you may see the object in the last station , and by the edge of the index from the point draw a line . Again , turn about the index with its edge to the same point , and through the sights ...
... edge of the index , so as through the sights ' you may see the object in the last station , and by the edge of the index from the point draw a line . Again , turn about the index with its edge to the same point , and through the sights ...
Página 163
... edge of the index to the second station , direct your sights to the next ; draw a line by the edge of the index , and lay off the next line ; and pro- ceed through the whole without using the needle , as you do with the theodolite . If ...
... edge of the index to the second station , direct your sights to the next ; draw a line by the edge of the index , and lay off the next line ; and pro- ceed through the whole without using the needle , as you do with the theodolite . If ...
Otras ediciones - Ver todas
A Treatise of Practical Surveying: Which Is Demonstrated From Its First ... Robert Gibson Sin vista previa disponible - 2018 |
Términos y frases comunes
40 perches ABCD acres altitude Answer base bearing blank line centre chains and links chord circle circumferentor Co-fecant Secant Co-fine Co-tang column contained cyphers decimal decimal fraction diameter difference Dift Diſt distance line divided draw drawn east edge EXAMPLE feet field-book figures fore four-pole chains half the sum height hypothenuse inches instrument latitude logarithm measure meridian distance method multiplied needle number of degrees object off-sets parallel parallelogram perpendicular piece of ground plane Plate pole Portmarnock PROB protractor quotient radius right angles right line scale of equal second station sect semicircle side sights sine square root stationary distance stationary line sun's survey taken tangent thence theo theodolite thro trapezium triangle ABC trigonometry true amplitude two-pole chains vane variation Vulgar Fraction whence ΙΟ
Pasajes populares
Página 32 - 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 199 - ... that triangles on the same base and between the same parallels are equal...
Página 94 - 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 23 - 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.
Página 95 - TO THEIR DIFFERENCE ; So IS THE TANGENT OF HALF THE SUM OF THE OPPOSITE ANGLES', To THE TANGENT OF HALF THEIR DIFFERENCE.
Página 37 - ABDE+ACGF the sum of the squares —BKLH-\-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 24 - Things that are equal to one and the same thing, are equal to each other. 2. Every whole is greater than its part. % 3. Every whole is equal to all its parts taken together. 4 If to equal things, equal things be added, the whole will be equal. 5. If from equal things, equal things be deducted the remainders will be equal.
Página 36 - XIII. •All parallelograms on the same or equal bases and between the same parallels...
Página 182 - VI. To find the content of a triangular piece of ground, Multiply the base by half the perpendicular, or the perpendicular by half the base ; or take half the product of the base into the perpendicular. The reason hereof is plain, from cor.
Página 35 - Triangles upon equal bases, and between the same parallels, are equal to one another.