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1 <br />VIIL <br />TABLE IL -- Radii, Ordinates and Deflections. Chord =100 ft. <br />Deg. <br />Radius - <br />Mid. <br />Ord. <br />Tan. <br />Dist. <br />I Def. <br />Dist. <br />I r <br />1 or <br />Deg. <br />Radius <br />Mid. <br />Ord. <br />Tan. <br />Dist. <br />Def. <br />Dist. <br />Doi' <br />1 Ft <br />2° 58' <br />t. <br />t. <br />it. <br />ft. <br />1° 59' <br />2°25' <br />t. <br />ft. <br />I ft. <br />ft. <br />171.01 <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 />6.685 <br />13.37 <br />2.30 <br />56 <br />6875.5 <br />.182 <br />.727 <br />1.454 <br />0.25 <br />8 <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 />7.556 <br />15.11 <br />2.60 <br />30;, <br />3819:8 <br />.327 <br />1.309 <br />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 />-3137.9 <br />.3641.454 <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 <br />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 />1.10. <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 />2155:7 <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 />2.327 <br />4.654 <br />0.80 <br />30 <br />499.1 <br />2.511 <br />10.02 <br />20.04 <br />3.45 <br />50' <br />2022:4 <br />.618 <br />2.472 <br />4.945 <br />0.85 <br />12 <br />478.3 <br />2.620.10.45 <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 />22.64 <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 />11.75 <br />23.51 <br />4.05 <br />30 <br />16637;3 <br />.764 <br />3.054 <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 />501195.0 <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 />1132.7 <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 <br />3.635 <br />7.271 <br />1.25 <br />16 <br />359.3 <br />3.496 <br />13.92 <br />27.84 <br />4.80 <br />20":1322.5 <br />.945 <br />3.718 <br />7.5G1 <br />1.30; <br />30 <br />348.5 <br />3.606 <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 />18 <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 />4.507 <br />9.014 <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 <br />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 <br />1.200 <br />4.798 <br />9.596 <br />1.65 <br />•23 <br />250.8 <br />5.035 <br />19.94 <br />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. <br />44.99 <br />7.80 <br />16 <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 <br />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 <br />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 />1.455 <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 (C) is equal to .0012 C' <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 />sin. Ig def: ang. <br />3/2 sub chord = sin of $ def. angle <br />R. <br />Length <br />of arc <br />for 100 ft. <br />12.5 Ft. <br />15 Ft. <br />20 Ft. <br />25 Ft. <br />300 <br />193.18 <br />I° 51' <br />2° 17' <br />2° 58' <br />3° 43' <br />101.15 <br />. <br />320 <br />181-.39 <br />1° 59' <br />2°25' <br />3° 10' <br />3° 58' <br />101.33 <br />34° <br />171.01 <br />20 o6' <br />20 33' <br />30 21' <br />4° 12' <br />101.48 <br />360 <br />16i.8o• <br />2°13' <br />z°41' <br />3°33' <br />4026' <br />1o1.66 <br />4 <br />-153.58 <br />20 20' <br />20 49' <br />3° 44' <br />4° 40' <br />Io1.85 <br />,380 <br />400 <br />146.19 <br />20 27' <br />2° 57' <br />3° 55' <br />.4° 54' <br />102.o6 <br />42° <br />139•.52 <br />2° 34 <br />30 05' <br />4° 07' <br />50 08 <br />102.29' <br />440 <br />133.47 <br />2° 41' <br />3° 13' <br />4° 18' <br />5° 2z' <br />102.53 <br />46° <br />127.97 <br />2° 48' <br />3° 21' <br />4° 29' <br />5° 36' <br />102.76 <br />48° <br />I2z.9z <br />z0 55' <br />3° 29' <br />4° 40 <br />5° 50' <br />103.00 <br />500 <br />118.31 <br />3° 02' <br />30.38' <br />4° 51' <br />60 04' <br />103.24 <br />52° <br />14. o6 <br />3009 . <br />5° 46. <br />5°.02' <br />60 17' <br />103.54 <br />540 <br />110.11 <br />30 16' <br />3° 54' <br />5° 13,6° <br />31' <br />103.84 <br />56° <br />Io6. 5o <br />30 22' <br />40 02' <br />5° 23' <br />6044 <br />10.4.14 <br />58° <br />103.14 <br />3° 29' <br />4° 10'... <br />5° 34' <br />6° 57 <br />104.43 <br />60° <br />100.00 <br />3035 <br />.4o 18' <br />5044, <br />7011' <br />104.72 <br />1X <br />CURVE FORMULAS <br />T= R tan 2 I R= T cot. I chord= <br />T - 5o. tan 2 I 2 Chord def. = R <br />Sin. 12 D 50 . <br />50 B __ Sin. i D I' <br />Sin. '2,D = R No. chords = <br />E' =Rex. sec z I D <br />Sin..2 D5o tan z I E = T tan } I Tan. def. = 2 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 .01745 (def. for I for 1 ft. <br />see Table lI.)i and divide given deflection by the product. <br />Rule -2. Multiply given deflection by 57.3, and divide the product by <br />the -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=Ioo.5 hyp. <br />Given Hyp. loo; Alt. 25.252=200=3:125. 100-3.125=96.875=Base. <br />Error_ in first example, .002; in last, .045• <br />To find Tons of Rail in one mile of track: multiply weight per yard <br />by I I, and divide by 7. <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 di, d2, d3, 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= Eds <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 />1t <br />.0167 <br />11/ <br />.1833 <br />21/ <br />.3500 <br />311, <br />.5167 <br />411 <br />.6833 <br />51/ <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 />N14. <br />.2333 <br />24 <br />.4000 <br />34 <br />.5667 <br />44 <br />.7333 <br />54 <br />.9000 <br />5' <br />0833 <br />15 <br />.2500 <br />25 <br />.4167 <br />35 <br />.5833 <br />45 <br />.7500 <br />55 <br />.9167 <br />6 <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 />17 <br />.2833 <br />27 <br />.4500 <br />37 <br />.6167 <br />47 <br />.7833 <br />57 <br />.9500 <br />8 <br />.1167 <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 />1 .1667 11 <br />20 <br />1 .3333 11 <br />30 <br />1..5000 11 <br />40 <br />1 .6667 11 <br />50 <br />1 .5333 11 <br />60 <br />11.0000 <br />TABLE V. -Inches in Decimals of a Foot. <br />1-16 3-32 3-16 % 5-16 I I <br />.0052 .0078 .0104 .0156 .0208 .0260 .0313 .0417 .0521. .0625 .0729 <br />0833 I .1667 I .2500 .3333 .4167 I .5000 -.5833 .6667 .7500 .8333 I .9167 <br />