TACHEOMETER OR STADIA TABLE FOR THE REDUCTION OF
INCLINED SIGHTS-Continued.
Distance Height Distance Height Distance Height Distance Height
Cos. Cos x Sin. Cos2. Cos x Sin Cos2. Cos x Sin. Cos". Cos x Sin
.8345737158.82139.38302.80783.39400 .79389.40451
.83413.37196.82095.38340.80737.39436.79342.40485
.83367.37235.82050.38377.80691.39472 79295 .40520 .83326.37274.82006.38414.80645.39508.79248 .83283.37313.81961.38452.80599.39543.79201.40587
.83240.37351.81916.38488.80553.39579 .79153.40621 .8319637390.81870.38526.80507.39615 .791c6.40655 .83153.37428 .81824.38563.80461.39650.79059 .40689 .8310937467.81780.38600 .80415.39685.79011 .40722
.83066.37505.81736.38637.80369.39721.78964.40757
.8302237543.81692.38673.80323.39756 .78917.40790
.82978.37582.81648.38710 .80276.39791.78869.40823
.82846.37697 .81512.38821.80137.39897.78726.40924
.82935.37620.81602.38748.80230.39827.78822.40857 .82890.37659.81557.38784.80184.39862.78774.40891
.8271537812.81375 .38930.79998.40002.78583
.8280337735.81466.38857.80091.39932.78679.40958 .82759-37773.81420.38894.80044.39967.78631.40990 .41024 .82671.37850.81330.38967.79952.40036.78536 .41058 .37888 .81284.39003 .79905.40071.78488.41090 .82583.37926.81239.39039.79858.40106.78440.41124 .82539.37964 .81194 .39076 .79812.40141.78392 .41156 .82494 38002 .81149.39112.79764 .40176 .78344 .41190 .82450.38039 .81103.39149 .79718.40210 .78296 .41223 .82406.38077 .81057 .39185.79671.40245.78248.41256 .82362.38114.81012 .39221 .79624.40279.78200 .41288 .82318.38152.80966.39257.79576.40314.78152.41322 .82273.38190.80920.3929379531.40348.78104.41354 .82228 .38227 .80875.39329.79484 .40382.78056.41386 .82183.38265.80829.39365.79436 .40416.78008 .41419 .82139.38302 .80783.39400 .79389 .40451.77960 .41452
f+d=0.75 0.68 0.31 0.68 0.32 0.67 0.33 0.66
f+d=1.00 0.91 0.41 0.90 0.43 0.89 0.45
f+d=1.25 1.14 0.52
1.13
0.54 1.12 0.56
TACHEOMETER OR STADIA TABLE FOR THE REDUCTION OF
INCLINED SIGHTS-Continued.
BROAD, surveys, 393 to 422
Absolute length of steel tape, 447
Abutments, setting out bridge, 252
Adjustment of chain, 4, 202; of theo-
dolite, 202 to 211; of sextant, 332,
333; of box sextant, 211; of com-
pass, 211, 212, 213; of dumpy
level, 213 to 216; of Y level, 216,
217, 191 to 197; of closing error
of traverse, 98 to 102
Alignment of tunnels, 285 to 310
Angles, setting out right, 4, 5, 12;
measuring with theodolite, 82, 83,
85 to 92, 96, 97, 459 to 462, 471,
473; with box sextant, 74, 106;
with sextant and artificial horizon,
335; oblique with sextant, 337;
reduction of oblique to horizontal,
337; with plane table, 109; by
photographic surveying, 112; pro-
tracting and plotting, 122, 92; of
curves, 236; for tunnels, 295;
measurement of small vertical with
bubble tube, 129; accurate methods
of observing for trigonometrical
surveys, 459 to 462, 471, 473;
time for observing, 461; accuracy
of observations of, 462; night ob-
servations of, 462, 443; reduction
of, to centre of station, 462; cor-
rection of errors of, 97, 101, 464 to
467; calculation of spherical excess,
464; calculation of, in spherical
triangles, 467; formula for spheri-
cal, 384; weights of observations
of, 466
Aneroid barometer, 171, 172; levelling
with, 165 to 170; tables, 170, 486,
493
Approximate measurement of distances,
107, 108, 78, 79
Aqueduct, survey of, 315
Areas, measures of, 50, 51; computa-
tion of, 51, 52, 53, 124, 125, 126,
419, 416; instruments for measur-
ing, 53, 54, 55, 56
Arlberg Tunnel, 308
Arrows, chaining, 3
Artificial horizon, 335; small altitudes
and depressions with, 335; use of,
336
Astronomical observations used in sur-
veying, 331 to 392; necessity for,
338; for meridian, 341 to 367;
example of meridian by equal alti-
tudes of circumpolar star, 346; ex-
ample of meridian by circumpolar
star at elongation, 352; example
of meridian by extra meridian ob-
servation of sun, 361; errors in
calculated meridian, 360, 361, 364;
for latitude, 367 to 373; example
of latitude by meridian observation
of sun, 371; accuracy of latitude
observations, 371; for time, 374 to
377; for longitude, 377 to 384;
example of difference of longitude
by watch, 379; latitude and longi-
tude by account, 347 to 350; time
of star's culmination or elongation,
353; example of calculation of,
353; star's altitude at elongation,
354; convergence of meridians,
366; explanation of astronomical
terms, 388 to 392; co-ordinates of
trigonometrical stations, 468
Astronomical terms, explanation of,
388 to 392
Attraction of compass needle, 104,
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ANKS and cuttings, 230 to 249;
centre lines and levels in, 252;
shrinkage and settlement of, 253;
levelling in slopes of, 249
Barometer, levelling with, 165 to 174;
aneroid, 171, 172; mountain, 172,
173, 174; tables for, 482 to 493
Base lines, 423 to 431, 435, 436, 471;
measurement of, 443 to 454, 427;
apparatus for measuring, 427, 430,
445, 446, 447; reduction of, to
sea level, 454, 425; reduction of,
to horizontal, 454; broken, 454;
extension of, 455
Bate range finder, 79
Beacons, 329
Bearings, 90, 91, 92,
106, 393 to 422,
ting, 123, 92
Bell-Elliott tangent reading tacheo-
meter, 257, 259
96, 97, 102, 103,
317 to 330; plot-
Bench marks, 139, 253; in tunnels,
304; for marine work, 326; abroad,
407
Boning rods, 161, 162, 253
Box sextant, 73; use of, 74, 75; theory
of, 74, 75; surveying with, 106;
adjustment of, 211
Bridges, 236; setting out foundations
of, 250; setting out abutments of,
252
Bridges Lee photo-theodolite, 113
Bubble tube of spirit level, 127; radius
of curvature of, 128, 188; sensi-
bility of, 128, 129, 182, 183, 189;
angular value of one division of,
129, 130, 191, 194, 183, 188, 189;
accurate measurement of small
vertical angles by, 129, 130; to
replace broken, 210; adjustment
of, 213 to 217, 191 to 197
Buildings, fixing positions of, on survey,
ANT of rails, 246
Care of instruments, So
Chain, 66 ft., 1, 2; 100 ft., I, 2; 20
metre, 2; reading, 2; laying out
on ground, 2; adjusting, 4, 202;
use of, 8; testing, 16; survey, 16,
20 to 41; incorrect, 49, 56; Ord-
nance Survey, 427
Chaining, 8; on slopes, 9, 10; accuracy
of, 10, 11; across a river or past
an obstacle, 11, 12, 13, 14, 87, 88
Chain lines, general principles of laying
out, 19; also 19 to 41, 85 to 91,
96, 97
Chainmen, 16, 234
Change points, 162
Checks on chain lines, 16, 17; on bear-
ings, 90, 91; on unclosed traverse,
96, 97, 413; on closed traverse,
97; on plotting of closed traverse,
98
Clinometer, 148, 149; use of, 148, 149;
cross sectioning with. 149, 150
Closing error, example of graphic ad-
justment of, 98, 99; example of
adjustment by calculation, 99, 100;
other methods of adjustment of,
IOI, 102; amount of, allowed in
practice, 102, 420; examples of,
108, 419, 98, 99
Coast line, survey of, 317, 318, 319,
324, 326
Coefficient of expansion of steel tapes,
447
Colby's base-measuring apparatus, 427
Collimation line, 60; adjustment of,
205 to 208, 213, 184, 192, 196,
197
Colouring plans, 47
Compass, 70, 71; Whitelaw's, 71, 72,
73, 397; prismatic, 75, 76, 408,
106, 108; pocket, 76, 77; traverse
surveys, 102, 103, 106, 108, 397 to
401; variations of, 103, 104; dip
of needle, 104; attractions of
needle, 104, 105; surveying with
pocket, 109; adjustment of, 211
to 213
Computing scale, 55
Conduit, survey of, 315
Contours, 151, 152; vertical distance
between, 152; determination of,
153; interpolation of, 153, 154,
155; sketching and inking in, 156;
contents from, 156; for road and
railway surveys, 225, 226, 227; by
tacheometry or stadia surveying,
255 to 284; example of, for rail-
way survey, 284; for road and
railway surveys abroad, 393 to 416
Conventional signs for delineating ob-
jects on plans, 48
Convergence of meridians, 366
Co-ordinates of traverse surveys, 90 to
102, 419, 420; rectangular spheri-
cal, 469; polar spherical, 469;
astronomical, of trigonometrical
stations, 468, 469
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