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/1'1/44bA <br />CDA'[, <br />'t'6 Q <br />d <br />�. <br />e� 0 <br />7,7 <br />61 <br />r <br />? <br />n <br />u <br />'Fit 76 <br />R <br />S.O <br />(yam �$'G/ <br />/ /1193,94 <br />1 <br />y f73! V 7-5S <br />13 3. <br />CURV TABLES. <br />Published by KEUFFEL & ESSER CO., 7 . <br />y `HOW TO USE CURVE TABLES. <br />Table I. contains Tangents and Externals to a 1° curve. Tan. and/^ �} <br />Ext.�C� �ylthe�adius maybefound nearly enough, by dividing theTan. <br />or of gppo§i'te the'given Central Angle by the given degree of curve. <br />To find Deg'. of Curve, having the Central Angle and Tangent: <br />Divide Tan. opposite the given Central Angle by the given Tangent. <br />To find -)Deg: of Curve, having the Central Angle and -External:G- <br />DiQe' hxtro posite the given Central Angle by the given External. <br />To find Nat: Tan. and Nat. Ex. Sec. for any angle by Table I.: Tan. <br />or Ext. of twice the given angle divided by the radius of a 1° curve will <br />be the Nat. Tan. or -Nat. Ex. Sec. S46-3 A/ <br />C� <br />3,.-5 - EXAMPLE. S-7�15.T S <br />Wanted a Curve with an Ext. of about 12 ft. Angle <br />of Intersection or I. P. =230 20' to the R. at Station <br />542+72. <br />Ext. in Tab. I opposite 23° 20' =120.87 <br />120.87--.12=10.07. Say a 10p Curve. <br />Tan. in Tab. I -opp. 23° 20'=1183.1 <br />1183.1=10=118.31. <br />Correction for A. 23° 20' for a 10° Cur. =0.16 - <br />118.31+0.16=118.47 =corrected Tangent. <br />(If corrected Ext. is required find in same way) �* / <br />�2 2 Ang.•23°20'=23.33°;=10=2.3333=L. C. G� , <br />`2° 191' = def. for sta. 542 I. P. = sta. 542+72 <br />4° 491' _ +50 Tan. = 1 .18.47 <br />q�°,49'= 43 <br />" " { 50 B. C.=sta. 541+53.53 3 <br />116 40' _ " " 'f 543 L. C. = 2 .33.33 <br />86.86 E. C. = Sta. 543+86.86 <br />100-53.53=46.47X3'(def. for 1 ft. of 10° Cur.) =139.41'= <br />2° 191'=def, for sta. 542. <br />Def. for 50 ft. =2° 30' for a 10° Curve. - (?y <br />Def, for 36.86 ft. =1' 501' for a 10° Curv& <br />>z �,�g <br />- I.P.An9.23'EO• � - <br />10• Gu w <br />4 <br />