Laserfiche WebLink
c <br />i <br />CURVE TABLES. <br />Published by KEUFFEL &s ESSER CO. <br />g <br />HOW TO USE CURVE TABLES. <br />Table I, contains Tangents and Externals to a 1° curve. Tan. and <br />Ext. to any other radius may be found nearly enough, by dividing the Tan. <br />or Ext. opposite 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: <br />Divide Ext. opposite 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 bf a 1° curve will <br />be the. Mat. Tan. or Nat, Ex, See. <br />EXAMPLE. <br />Wantecl a Curve with an Ext. of about 12 ft. Angie <br />of Intersection or 1. P.=23* 20' to the R. at Station <br />542--{-72. <br />Ext. in Tab. I opposite 23° AY =120.87 <br />120.87=12=10.07. Say a 10° Curve. <br />Tan. in Tab. I opp. 23° 20' =1183.1 <br />17 <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 />i <br />(If corrected Ext. is required find in sante way) <br />Ang.23°20'=23.33°-10=2.3333=L. C. - <br />20 191'=def. forsta. 542 1. P. =sta. 542+72 <br />4°49x'= ti ¢ a . {-50. Tan. = 1 ,18.47 <br />At=7' <br />19,' = « Y a 543 <br />9° 49a' = t° "' « 5650 B. C. =sta. 541+53.53 <br />11' 40' = 543 + L. C.= 2 , 33.33 <br />86.86 E. C.=Sta. 543-{-86.86 <br />100-53.53=46.47X3'(dcf. for 1 ft, of 10' Cur.) =139.41= <br />2° 19 a'=def. for sta. 542. <br />Def. for 50 ft. =2' 30' for a 10° Curve, <br />Def. for 36.86 ft. =1° 501' for a IQ° Curve. <br />