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e CURVE TABLES Published by KEUFFEL & ESSER CO. HOW TO USE CURVE TABLES Table I. contains Tangents and Externals to a P curve. Tan. and Ext. to any other radiusmay befound nearly enough, by dividing the Tan. or Ext. opposite the given Central Angle•by the given degree of curve. To find Deg. of Curve, having the Central Angle and Tangent: Divide Tan, apposite the given Central Angle by the given Tangent. To find Deg. of Curve, having the Central Angle and External: LDivide Ext. opposite the given Central Angle by the given External. To find Nat—Tan. and Nat. Ex. Sec. for any angle by Table I.: Tan. or Ext. of twice the given angle divided by the radius of a 1' curve will 6e the Nat. Tan. or Nat. Ex. Sec. EXAMPLE 1 Wanted a Curve with an Ext. of about 12 ft. Angle of Intersection or 1. P.=23' 20' to the R. at Station 542+72.. _ Ext. in Tab. I opposite 23' 20'= 120.87 120.87 =12 —10.07. Say a 10' Curve. Tan. in Tab.] opp. 23' 20'=1183.1 1183.1'=10=118.31.. Correction for A. 23'20' for a 10' Cur. =0.16 118.31+0.16=118.47=corrected Tangent. (1f corrected Ext. is required find in same way) Ang.23'20'=23.33'=10=2.3333=L. C. 2' 19 def. for sta. 542 I. P. =sta. 542+72 40 49i' = ' " a +50 Tan. = 1 . 18.47 7' 19j'= a u 543 9' 49j'-- +50 B. C. sta. 541+53.53 53.53 11' 40' _ " 543+ L. C. = 2 .33.33 86.86 E. C.=Sta. 543+86.86 100-53.53=46.47X3'(def. for I ft. of 10' Cur.)=139.41'= 2' 192' =def, for sta. 542. v Def, for 50 ft. =2' 30' for a 10' Curve. Def, for 36.86 ft. =1' 50j' for a 10' Curve. ' s , i r e CURVE TABLES Published by KEUFFEL & ESSER CO. HOW TO USE CURVE TABLES Table I. contains Tangents and Externals to a P curve. Tan. and Ext. to any other radiusmay befound nearly enough, by dividing the Tan. or Ext. opposite the given Central Angle•by the given degree of curve. To find Deg. of Curve, having the Central Angle and Tangent: Divide Tan, apposite the given Central Angle by the given Tangent. To find Deg. of Curve, having the Central Angle and External: LDivide Ext. opposite the given Central Angle by the given External. To find Nat—Tan. and Nat. Ex. Sec. for any angle by Table I.: Tan. or Ext. of twice the given angle divided by the radius of a 1' curve will 6e the Nat. Tan. or Nat. Ex. Sec. EXAMPLE 1 Wanted a Curve with an Ext. of about 12 ft. Angle of Intersection or 1. P.=23' 20' to the R. at Station 542+72.. _ Ext. in Tab. I opposite 23' 20'= 120.87 120.87 =12 —10.07. Say a 10' Curve. Tan. in Tab.] opp. 23' 20'=1183.1 1183.1'=10=118.31.. Correction for A. 23'20' for a 10' Cur. =0.16 118.31+0.16=118.47=corrected Tangent. (1f corrected Ext. is required find in same way) Ang.23'20'=23.33'=10=2.3333=L. C. 2' 19 def. for sta. 542 I. P. =sta. 542+72 40 49i' = ' " a +50 Tan. = 1 . 18.47 7' 19j'= a u 543 9' 49j'-- +50 B. C. sta. 541+53.53 53.53 11' 40' _ " 543+ L. C. = 2 .33.33 86.86 E. C.=Sta. 543+86.86 100-53.53=46.47X3'(def. for I ft. of 10' Cur.)=139.41'= 2' 192' =def, for sta. 542. v Def, for 50 ft. =2' 30' for a 10' Curve. Def, for 36.86 ft. =1' 50j' for a 10' Curve.