A treatise on land surveying [ed.] by W. Galbraith1849 |
From inside the book
Results 1-5 of 36
Page 20
... eye - sketch or in a field - book . ABCDEF is a field of six sides , surveyed with the chain , the fences of which are all straight . The best method of measuring this field is to divide it into triangles on the spot , which is repre ...
... eye - sketch or in a field - book . ABCDEF is a field of six sides , surveyed with the chain , the fences of which are all straight . The best method of measuring this field is to divide it into triangles on the spot , which is repre ...
Page 21
... eye - sketch or a field - book , whichever you choose to keep . A 1200 1200 1420 1000 1400 650 1500 To plot and delineate a plan of this fig . Draw any one of the lines you choose to begin at by random with a black - lead pencil , to ...
... eye - sketch or a field - book , whichever you choose to keep . A 1200 1200 1420 1000 1400 650 1500 To plot and delineate a plan of this fig . Draw any one of the lines you choose to begin at by random with a black - lead pencil , to ...
Page 22
... eye - sketch , it is now to be delineated and laid down by scale and compasses . Draw a line at pleasure to represent the longest side , A C , with a black lead pencil , and take off the distance 900 from a scale of equal parts , which ...
... eye - sketch , it is now to be delineated and laid down by scale and compasses . Draw a line at pleasure to represent the longest side , A C , with a black lead pencil , and take off the distance 900 from a scale of equal parts , which ...
Page 35
... eye - sketch , I now have to show the method of making out a plan from the eye - draught that was kept when the survey was taken . Draw a line at pleasure to represent the line A B ; choose any scale you think proper , suppose two ...
... eye - sketch , I now have to show the method of making out a plan from the eye - draught that was kept when the survey was taken . Draw a line at pleasure to represent the line A B ; choose any scale you think proper , suppose two ...
Page 37
... eye- sketch . ) Again an offset was taken of 160 to the river at C , and another of 400 to the corner of the river and a fence ; the cross staff was placed at C , and a back sight taken to B , and a fore sight or perpendicular to D ...
... eye- sketch . ) Again an offset was taken of 160 to the river at C , and another of 400 to the corner of the river and a fence ; the cross staff was placed at C , and a back sight taken to B , and a fore sight or perpendicular to D ...
Other editions - View all
Common terms and phrases
A R P acres altitude angle axis azimuth back sight bearing was taken Bearings and Distances Bonnyton calculation centre chain circle column compasses computed corner correct cosec decimals degrees divided division draw edge equal error eye-sketch feet fence field-book figure formula give Goatfell ground horizontal inches Inchkeith Indian ink INNERLEITHEN insert intersect latitude length limb logarithm longitude mark mean measuring that line meridian method move it parallel multiplied needle observations offset parallax parallel ruler perches perpendicular plant the instrument Plate plotting pole placed protracted protractor put one foot radius reduced right ascension river road roods scale screw sextant side spherical excess square links ST MARY'S LOCH staff station sun's survey surveyor take a back take a bearing telescope theodolite trapezium triangle Trigonometrical Survey turn the telescope vane vernier vertical wide zenith-distance
Popular passages
Page 476 - The level, which is shown under and parallel to the telescope, is attached to it at one end by a joint, and at the other by a...
Page 238 - or nearly; that is, the difference between the true and apparent level, is equal to the square of the distance...
Page 194 - 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.
Page 476 - ... parallel to the optical axis of the telescope, or line of collimation ; the screw, g, at the opposite end, is to adjust it laterally, for true parallelism in this respect. The telescope has two collars, or rings, of bell metal, ground truly cylindrical, on which it rests in its supports...
Page 480 - Now release the upper plate, and move it round by hand till the telescope is directed to the second object, whose angular distance from the first is required...
Page 498 - ... to the horizon. The levelling of the axis, as it is called, is therefore one of the most important adjustments of the instrument, and is effected by the aid of a spirit-level, E, which is made for this purpose to stride across the telescope, and rest on the two pivots. The standards, DD, are fixed by screws upon a brass circle, F, which rests on three screws...
Page 5 - ... and Minuit was drowned. MINUTE, a unit of time equal to 60 seconds. There are 60 seconds in one minute and 60 minutes in one hour. MINUTE, in angular measurement, the sixtieth part of a degree in the sexagesimal system. In this system the circumference of a circle— one complete revolution— is divided into 360 equal parts called degrees, the degree is divided into 60 equal parts called minutes, and the minute is divided into 60 equal parts called seconds. The symbol for the degree is °, the...
Page 486 - ... with the load it carries, is prevented from pressing too heavily on its bearings, by two friction rollers on which it rests, one of which is shown at e. A spiral spring, fixed in the body of each pillar, presses the rollers upwards, with a force nearly a counterpoise to the superincumbent weight; the rollers on receiving the axis yield to the pressure, and allow the pivots to find their proper bearings in the Y's, relieving them, however, from a great portion of the weight. The telescope, K,...
Page 478 - ... of a distant object; then turn the telescope half round in its Y's till the level lies above it, and observe if the same point is again cut by the centre of the wire ; if not, move the wire...
Page 499 - ... has five vertical and two horizontal wires. The centre vertical wire ought to be fixed in the optical axis of the telescope, and perpendicular to a line drawn through the pivots of the axis. It will be evident, upon consideration, that these wires are rendered visible, in the day-time, by the rays of light passing down the telescope to the eye ; but at night, except when a very luminous object (as the moon) is observed, they cannot be seen. Their illumination is therefore effected by piercing...