Elementary text book for young surveyors and levellers |
From inside the book
Results 1-5 of 10
Page 1
... minutes must be guessed at . Now to lay off the given angle of 60 degrees from the line AB , look for 60 ° , counting from B B right to left , and make a mark on the INTRODUCTION Enumeration of the necessary Drawing Instruments ...
... minutes must be guessed at . Now to lay off the given angle of 60 degrees from the line AB , look for 60 ° , counting from B B right to left , and make a mark on the INTRODUCTION Enumeration of the necessary Drawing Instruments ...
Page 102
... compass box , is capable of being read off to minutes . Attached to this vertical arc , above it , is placed a tele- scope supported on two Ys or arms in the form of the letter Y. These Ys , which are tangents to the 102 LAND SURVEYING .
... compass box , is capable of being read off to minutes . Attached to this vertical arc , above it , is placed a tele- scope supported on two Ys or arms in the form of the letter Y. These Ys , which are tangents to the 102 LAND SURVEYING .
Page 104
... minutes . Again , unclamp the large clamp - screw , and turn the whole instrument towards the left of the stations , between which , you are desirous of taking the angle , until you can cut the object as accurately with the intersection ...
... minutes . Again , unclamp the large clamp - screw , and turn the whole instrument towards the left of the stations , between which , you are desirous of taking the angle , until you can cut the object as accurately with the intersection ...
Page 105
... minutes of the angle , measured between the two given objects . When the cross webs , therefore , nearly cover the object , clamp the plates as before , and use the tangent screw ( † ) ; and , with the magnifying glass ( m ) , read off ...
... minutes of the angle , measured between the two given objects . When the cross webs , therefore , nearly cover the object , clamp the plates as before , and use the tangent screw ( † ) ; and , with the magnifying glass ( m ) , read off ...
Page 107
... minute . Hence to ascertain the number of degrees and minutes contained in a given angle , observe where the broad arrow of the vernier is ; if , between a full degree and a half degree , so many degrees and as many minutes , as are ...
... minute . Hence to ascertain the number of degrees and minutes contained in a given angle , observe where the broad arrow of the vernier is ; if , between a full degree and a half degree , so many degrees and as many minutes , as are ...
Other editions - View all
Elementary Text Book for Young Surveyors and Levellers with Copious Field ... Henry James Castle No preview available - 2019 |
Elementary Text Book for Young Surveyors and Levellers With Copious Field ... Henry James Castle No preview available - 2019 |
Common terms and phrases
2nd gate A. R. P. Answer angle of bearing angle of elevation base line bisect broad arrow centre chain surveying chains 50 links CHAP CHECK ANGLES check line circle circumferentor clamp corner correct cross customary determined diagonal DIAGRAM distance ditch divided draw equal Euclid EXAMPLE fence field book field notes flag gate post given angle given line given point half degrees hedge height horizontal inch interior angles intersection join Lancashire length line AC long scale mark meridian line motion needle number of degrees object observation offsets perpendicular placed plot pond protractor Required the true right angles right-angled triangle river road roods round screws similar triangles spirit level square chains square feet statute acres statute measure taken telescope theodolite top of bank trapezium triangle ABC true bearing true north vertical whole instrument width Wiltshire Wood
Popular passages
Page 111 - All the interior angles of any rectilineal figure, together with four right angles, are equal to twice as many right angles as the figure has sides.
Page 160 - LEVELLING is the art of representing the inequalities of the earth's surface, and of determining the relative heights of any number of points above or below a line, equidistant, at every point, from the centre of the earth.
Page 17 - The square of the hypothenuse is equal to the sum of the squares of the other two sides ; as, 5033 402+302.
Page 8 - To describe a square upon a given straight line. Let AB be the given straight line : it is required to describe a square upon AB.
Page 102 - The existence of parallax is determined by moving the eye about, when looking through the telescope, observing whether the cross wires change their position, and are flittering and undefined. To correct this error, first adjust the eye-piece, by means of the moveable eye-piece tube, till you can perceive the cross wire clearly defined, and sharply marked against any white object.
Page 23 - C will be found 9, the square root on D. For the square root of 144 : Set 1 on C to 10 on D ; then against 144 on C will be found the square root 12 on D. 42. To find the area of a board or plank : The rule is, to multiply the length by the breadth, the product will be the area ; therefore, by the sliding rule, Set 12 on B against the breadth in inches on A ; then...
Page 16 - E, the adjacent angles CEA, AED; these angles are together equal to two right angles. (i. 13.) Again, because the straight line DE makes with AB...
Page 28 - To find the area of a circle. Rule — Multiply the square of the diameter by .7854; or the square of the radius by 3.1416; or the square of the circumference by .07958. Find the area of a piston 20 in. in diam. Answer— 20!
Page 8 - To draw a straight line at right angles to a given straight line, from a given point in the same. Let AB be the given straight line, and C the given point in it : it is required to draw from the point C a straight line at right angles to AB.
Page 23 - To find the Area of a Triangle when the Three Sides are given. Rule. — From half the sum of the three sides subtract each side separately. Multiply the half sum and the three remainders together, and extract the square root of the product.