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VIII <br />TABLE IL - Radii, Ordinates and Deflections. Chord =100 ft. <br />Deg.. <br />Radius <br />Mid. <br />Ord 'Dist. <br />Tan. <br />Def. <br />Dist ' <br />for <br />i Ft. <br />Deg. <br />Radius-Mid.,Tan.. <br />Oid. <br />, Dist, <br />Def. <br />Dist. <br />' Dor <br />I Ft. <br />2° 17' <br />2° ° <br />58' <br />3° 43'. <br />101.15 <br />'32° - <br />-- 181.39 <br />- -1° 59 <br />..202',5,-.- <br />3°_ , <br />10 <br />30 58,.. <br />101--33 <br />340 <br />0°10' <br />34377. <br />:.036 <br />..145 <br />..291 <br />0.05 ."= <br />7' <br />819.0 <br />1:528 <br />6.105 <br />12.21 <br />2.10 <br />20 <br />17189,. <br />.073 <br />.291 <br />582 <br />0.10 <br />20' <br />781.8 <br />1.600 <br />6.395 <br />12.79 <br />2.20 <br />30- <br />11459. - <br />.109 <br />' .436 <br />,..873 <br />0.15 <br />30 <br />764.5 <br />1.637 <br />6.540 <br />13.08 <br />2.25 <br />40'. <br />8594:4 <br />.145 <br />.582 <br />'_1:164 <br />0.20,•' <br />40'. <br />747.9 <br />1.673 <br />16.685 <br />13.37 <br />2.30 <br />50, <br />6875:5 <br />.182 <br />.727 <br />1.454 <br />0.25;;.5 <br />103.00 <br />716.8 <br />1.746 <br />6.976 <br />13.95 <br />2.40 <br />1 <br />5729.6 <br />.218 <br />.873 <br />'1.745 <br />0.30" <br />20 <br />688.2 <br />1,819 <br />7.266 <br />14.53 <br />2.50 <br />10 <br />4911.2 <br />.255 <br />1.018 <br />2.036 <br />0.35 <br />30 <br />674.7 <br />1.855 <br />,7.411 <br />14.82 <br />2.55 <br />20 <br />4297:3 <br />'.291 <br />1.164 <br />.2.327 <br />0.40" <br />40 <br />661.7 <br />1.892 <br />17.556 <br />15.11 <br />2.60 <br />30. <br />3819.8 <br />.327 <br />1.309'.2.618 <br />0.45. <br />-9 <br />637.3 <br />1:965 <br />.7.846 <br />15.69 <br />2.70 <br />40 <br />3437.9 <br />.364 <br />.1.454 <br />2.909 <br />0.50 <br />20 <br />614.6 <br />2;037' <br />8.136 <br />16.27 <br />2.80 <br />50 <br />3125.4 <br />'.400 <br />1.600 <br />3.200 <br />0.55 • <br />'' 30 <br />603.8 <br />2:074 <br />8.281'16.56 <br />2.85 <br />2''.- <br />2864.9 <br />.436 <br />1.745 <br />3.490 <br />0.60' <br />40: <br />593.4 <br />2:110 <br />'8:426 <br />16.85 <br />2.90 <br />10' <br />2644'.6 <br />.473 <br />1.891 <br />3.781 <br />0.65 <br />10 . <br />573.7 <br />2;183 <br />8:716 <br />17.43 <br />3.00 <br />20 <br />2455.7 <br />.509 <br />2.036 <br />4.072 <br />0.70 <br />30 <br />546.4 <br />2,292 <br />9.150 <br />18.30 <br />3.15 <br />30 <br />2292.0 <br />.545 <br />2.181; <br />4.363 <br />0.75 <br />11 <br />521.7 <br />2.402 <br />9.585 <br />19.16 <br />3.30 <br />40 <br />' 2148'.8 <br />.582 <br />2:32T <br />4.654 <br />0.80 <br />30, <br />499.1 <br />2.511 <br />10'.02'•-20.04 <br />3.45 <br />50'" <br />2022.4'..618 <br />2.472 <br />4.945 <br />0.85 <br />.12 <br />478.3 <br />2:620 <br />10.45 <br />20.91 <br />3.60 <br />3 <br />1910.1 <br />".655 <br />2.618 <br />5.235 <br />0.90' <br />30, <br />459.3 <br />2.730 <br />10.89 <br />21.77 <br />3..75 <br />.,10 <br />1809.6 <br />'.691 <br />2.763 <br />5.526 <br />0.95 <br />13 <br />441.7 <br />2.839 <br />11.32 <br />3.90 <br />20 <br />1719.1 <br />.727; <br />2.908 <br />;5:817 <br />1.00, <br />30 <br />425.4 <br />2.949 <br />,22.64 <br />11-.75' <br />23.51 <br />4.05 <br />30 <br />: 1637.3 <br />.764 <br />31054 <br />6.108 <br />1.05 <br />;14' <br />410.3 <br />3.058 <br />12.18 <br />24.37 <br />4.20 <br />40 <br />1562.9 <br />.800 <br />3.199 <br />6.398 <br />1.10 <br />30 <br />396.2 <br />3.168 <br />12.62 <br />25.24 <br />4.35 <br />50 <br />1495.0 <br />_ .836 <br />3..345 <br />6.689 <br />1.15 <br />.15 <br />383; 1 <br />3.277 <br />13.05 <br />26.11 <br />4.50 <br />4 '' <br />1432.7 <br />.873 <br />3.490 <br />6.980 <br />1.20- <br />- 30 <br />370:8 <br />3.387 <br />13.49 <br />26:97 <br />4.65 <br />10 <br />1375.4 <br />.909.3.635 <br />7.271 <br />1.25.' <br />16 .i <br />359.3 <br />:496 <br />13.92. <br />27.84 <br />4.80 <br />20, <br />1322:5 <br />` .945 <br />1.30 <br />3.718, <br />7.561 <br />30 <br />348.5 <br />.606 <br />14.35' <br />28.70 <br />4.95 <br />30 <br />1273.6 <br />.982 <br />3.926 <br />7.852 <br />1.35 <br />17 <br />338.3 <br />3.716 <br />14.78 <br />29.56 <br />5.10 <br />40 <br />1228:1 <br />1.018 <br />4.071" <br />8.143 <br />1.40 <br />1S <br />319.6 <br />3.935 <br />15.64 <br />31:29 <br />5.40 <br />50 <br />1185.8 <br />1.055 <br />4.217 <br />8.433 <br />1.45 <br />19: <br />302.9 <br />4.155 <br />16.51 <br />33.01 <br />5.70 <br />5 <br />1146.3 <br />1.091 <br />4.362 <br />8.724 <br />1.50 <br />20' <br />287.9 <br />4.374 <br />17.37 <br />34.73 <br />6.00 <br />-- 10- <br />1109.3 <br />1.127 <br />4.5071 <br />0.014 <br />1.55 <br />21' <br />274.4 <br />4.594 <br />18.22 <br />36.44 <br />6.30 <br />20, <br />1074.7.1.164 <br />4:653 <br />9.305 <br />1.60 <br />22 <br />262.0 <br />4.814 <br />19.08. <br />38.16 <br />6.60 <br />30" <br />1042:1'1.200 <br />4.798 <br />9.596 <br />1.65 <br />23 <br />250.8 <br />5.035 <br />19.94 :39.87 <br />6.90 <br />40, <br />1011.5 <br />1.237 <br />4.943 <br />.9.886 <br />1.70 <br />24. <br />240.5 <br />5.255 <br />20.79 <br />41.58 <br />7.20 <br />50 <br />982.6 <br />1.273 <br />5.088 <br />10.18," <br />1.75 <br />25 <br />231.0 <br />5:476 <br />21.64, <br />43.28 <br />7.50 <br />6 <br />955.4 <br />1-.309 <br />5.234 <br />10.47 <br />1.80 <br />26 <br />222".3 <br />5.697 <br />22.'50-;44:99 <br />7.80 <br />10 <br />929.6 <br />1.346 <br />5.379 <br />10.76' <br />1.85 <br />27 <br />214.2 <br />5.918 <br />23.35"'46.69 <br />8.10 <br />20 <br />'905.1 <br />1.382 <br />5.524 <br />11.05 <br />1.90 <br />28 <br />206.7 <br />6.139 <br />24.19 <br />48.38 <br />8.40 <br />30 <br />881.9 <br />1.,418 <br />5.669.11.34 <br />1.95 <br />29 <br />199.7 <br />6.360 <br />25.04 <br />50.07 <br />8.70 <br />40 <br />859.9 <br />1.4 55 <br />5.814 <br />11.63 <br />2.00 <br />30 <br />193.2 <br />6.583 <br />25.88 <br />51.76 <br />9.00 <br />The middle ordinate in inches for any cord of length (0) is egnal to ,0012 C2� <br />multiplied by the middle ordinate taken from the above table. Thus, if it <br />desired to bend a 30 ft. rail to fit a 10 degree curve, its middle ordinate should <br />be .0012X900X2.183 or 2.36 inches. <br />TABLE III. ', Deflections for Sub Chords for Short Radius Curves. <br />Degree <br />of <br />Curve <br />. Radius <br />50 <br />34 sub chor t <br />R = sin of i def. angle <br />Length <br />of arc <br />for 100 ft. <br />sin. I def. ang. <br />12.5, Ft. <br />15 Ft. <br />20 Ft. a <br />25 Ft. <br />30° <br />193.18 <br />1° 81' <br />2° 17' <br />2° ° <br />58' <br />3° 43'. <br />101.15 <br />'32° - <br />-- 181.39 <br />- -1° 59 <br />..202',5,-.- <br />3°_ , <br />10 <br />30 58,.. <br />101--33 <br />340 <br />171.0I <br />2° 06' <br />2° 33 <br />3° 21' <br />4° 12' <br />101.48 <br />36° <br />a61.80 . <br />:.2° 13'• - <br />2° 41' <br />3° 33' ; <br />_4° 26' <br />ioi .66 <br />38° <br />15.3.58 <br />2° 20' <br />2° 49'. <br />3° 44'. <br />4° 40' <br />101.85 <br />40° <br />•i46A§__,_^ <br />20 2.7'- <br />-i° 57' - <br />3°,55' <br />4°'54" ` <br />102.o6 <br />42° <br />139.52 <br />z° 34' <br />3° 05 <br />4° 07'- <br />g° 08 <br />IO2.29 <br />'440 <br />133-147., <br />20 41, <br />.-3° 13' <br />4° 18' <br />5° 22' <br />102.53 <br />46°.' <br />127.972,.48' <br />.. <br />3o 2I' <br />4° 29' '' <br />-5° 36' <br />102.76 <br />48° <br />(22.92 <br />2°55' <br />3°29' <br />4°40'. <br />5°50' <br />103.00 <br />.509 <br />118.31 <br />30 02' <br />3° 38'_ <br />4° 51' <br />6° 04' <br />103.24 <br />52° <br />114.06 <br />3° 09' <br />3° 46'' <br />5' Oz, <br />6° 17' <br />103 54 <br />54° <br />IIO.II <br />3° 16' <br />3° 54: <br />50 13' . <br />6° 31' <br />103.84 <br />560 <br />106.50 <br />3° 22 <br />4° 02'• <br />5° 23' <br />6° 44% <br />iO4. 14 <br />:58*1 <br />103.14 <br />30 29� <br />4o Io' <br />50 34f <br />60 57' <br />104.43 <br />60 <br />100.00 <br />3 .35 <br />4 18. <br />5 .44 <br />7 11 <br />104.72 <br />CURVE FORMULAS IX <br />T R tan 21 1 y R= T cot. l I Chord def. = chord' <br />r o tan -f I _ 2 _ <br />DR = 50 R . . <br />Sin. ll <br />Sin. a D = 5o . 2 No. chords = I <br />R. E = R ex. sec; I D <br />Sin. ;'D _ 5o t T ; I E = T tan } I Tan. def. = a chord def. <br />The square of any distance, divided by twice the radius, will equal <br />the distance from tangent to curve, very nearly. <br />To find angle for a given distance and deflection. <br />Rule I. Multiply the given distance by .01945 (def. for I° for I ft. <br />,see Table II.),.and divide given deflection by the product. <br />Rule 2. Multiply given deflection by 57.3, and divide the product by <br />fhe given distance. <br />To find deflection for a given angle and distance. Multiply the angle <br />by .01745, and the product by the distance. <br />GENERAL DATA <br />RIGHT ANGLE TRIANGLES. Square the altitude, divide by twice the <br />base. Add quotient to base for hypotenuse. <br />-Given-Base loo, Alt. 10.102 -200=.5. IOO+-5=1oo.5`hyp• <br />Given Hyp. loo, Alt. 25.252=200=3.125, loo -3.125=96.875 =Base. <br />Error in first example, .002; in last, .o45• - <br />-To find Tons of Rail in one -mile, of track: multiply weight per yard <br />-by.I I,, and divide by 9.. <br />LEVELING. The -correction for curvature 'and refraction, in feet <br />and decimals of feet is equal to 0.574d2, where d is the distance in miles. <br />The correction for curvature alone is closely, 'd2. The combined cor- <br />rection is negative. <br />PROBABLE ERROR. If d,, d2; ds, 'etc. are the discrepancies of various <br />results from the mean, and if Ede=the sum of the squares of these differ- <br />ences and n=the number of observations, then the probable error of the <br />mean = 2;d2 <br />-0.6745 n(n_1) <br />SOLAR EPHEMERIS. Attention is called to the Solar -Ephemeris for <br />the .current year; published by Keuffel & Esser Co., and furnished upon <br />"request. This handy booklet, 38x6 in., has about 190 pages of data very <br />useful to the Surveyor; such as the adjustments of transits, levels and solar <br />attachments; directions and tables for determining the meridian and the <br />latitude from observations on the sun and Polaris; stadia measurements; <br />magnetic declination; arithmetic. constants, etc. <br />TABLE IV. -Minutes in Decimals of a Degree. <br />1f <br />.0167 <br />111 <br />.1833 <br />211 <br />.3500 <br />311 <br />.5167 <br />41f <br />.6833 <br />511 <br />.8500 <br />2 <br />.0333 <br />12. <br />.2000 <br />22 <br />.3667 <br />32 <br />.5333 <br />42 <br />.7000 <br />52 <br />.8667. <br />.3 <br />.0500 <br />13 <br />.2167 <br />23 <br />.3833 <br />33 <br />.5500 <br />43 <br />.7167 <br />53 <br />.8833 <br />.4 <br />.0667 <br />14 <br />.2333 <br />24 <br />.4000 <br />34 <br />.5667 <br />44 <br />.7333 <br />54 <br />.9000 <br />5 ' <br />15 <br />.2500 <br />25 <br />.4167 <br />35 <br />.5833 <br />45 <br />.7500 <br />55 <br />.9167 <br />6 <br />.0833 <br />.1000 <br />16 <br />.2667 <br />26 <br />.4333 <br />36 <br />.6000 <br />46 <br />.7667 <br />56 <br />.9333 <br />7 <br />:1167 <br />17 <br />.2833 <br />'27 <br />.4500 <br />37 <br />.6167 <br />47 <br />.7833 <br />57 <br />.9500 <br />8 <br />1333 <br />18 <br />.3000 <br />28 <br />.4667 <br />38 <br />.6333 <br />48 <br />.8000 <br />58 <br />.9667 <br />9 <br />.1500 <br />19 <br />.3167 <br />29 <br />.4833 <br />39 <br />.6500 <br />49 <br />.8167 <br />59 <br />.9833 <br />10 <br />.1667 <br />20 <br />.3333 <br />30 <br />.5000 <br />40 <br />.6667 <br />50 <br />1 .8333 11 <br />60 <br />11.0000 <br />_ <br />TABLE V. <br />-Inches in Decimals of a Foot. <br />1-16 3-32Y <br />3-16 <br />% <br />5-16 <br />Y2' <br />.0052 .0078 <br />.0078 Ij <br />.0104 <br />.0156 <br />0208 <br />.02660 <br />.0313 <br />04817 <br />.0521 <br />.06225 <br />.0 <br />729 <br />I <br />1 <br />10 <br />.0833 I .1667 I <br />.2500 <br />.3333 <br />.4167 <br />.5000 <br />.5833 <br />.6667 <br />.7500 <br />.8333 <br />.9167 <br />