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I'1. ::CURVE- & ESSER-CO � Published by KEUFFEL ' HOW 'TO USE CURVE TABLES Table I: contains Tangents:and Externals to a 1° curve. Tan. and Ext. to any other radius Ypay be found nearly enough, by dividing theTan. } ! �r Ext. oppo? ite the given Central. Angle by the given degree.of curve. I To find Deg. of Curve, having the Central -Angle and Tangent: i ivide Tan. opposite the given Central Angle by the given Tangent. -To find Deg_. of Curve, having the Centras. Angle and'External: p , (Divide Ext. opposite the given Central Angle.by the given External. find. Nat. Tan: and Nat. Ex. See. for any angle by Table I.: Tan. .,To ar Ext. of twice the given angle -divided by the radius of a 1° curve,will be the Nat. Tan. or Nat.'Ex. See. EXAMPLE Wanted a Curve with an Ext. of about 12 ft. Angle dor P.=23° 20' the R. at' Station of Intersection .1:. -to. • 542-�72. ' '. �ii Ext. in Tab. I opposite 23°.20' 2120.87 120.87--12=10.07. Say a 10° Curve. Tan in Tab I opp 23' 20'=1183.1 ;1-183.1-i-tf)=118.31: ....° ' - Correction for A 23o '20 -[ora 10 : Cur. =0.16 t r 118.31-}-0 16 —118 47 = corrected Tangent. (If corrected Fxt 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 +50 Tan.'=1 ..:18.47 '- --'• 7 = ° 192' .0 °. 543 S. C.=sta. 541-X53.53 11* 40,.= u . « �.. 543 } . L. C. __ 2 .33.33 4 I'1. ::CURVE- & ESSER-CO � Published by KEUFFEL ' HOW 'TO USE CURVE TABLES Table I: contains Tangents:and Externals to a 1° curve. Tan. and Ext. to any other radius Ypay be found nearly enough, by dividing theTan. } ! �r Ext. oppo? ite the given Central. Angle by the given degree.of curve. I To find Deg. of Curve, having the Central -Angle and Tangent: i ivide Tan. opposite the given Central Angle by the given Tangent. -To find Deg_. of Curve, having the Centras. Angle and'External: p , (Divide Ext. opposite the given Central Angle.by the given External. find. Nat. Tan: and Nat. Ex. See. for any angle by Table I.: Tan. .,To ar Ext. of twice the given angle -divided by the radius of a 1° curve,will be the Nat. Tan. or Nat.'Ex. See. EXAMPLE Wanted a Curve with an Ext. of about 12 ft. Angle dor P.=23° 20' the R. at' Station of Intersection .1:. -to. • 542-�72. ' '. �ii Ext. in Tab. I opposite 23°.20' 2120.87 120.87--12=10.07. Say a 10° Curve. Tan in Tab I opp 23' 20'=1183.1 ;1-183.1-i-tf)=118.31: ....° ' - Correction for A 23o '20 -[ora 10 : Cur. =0.16 t r 118.31-}-0 16 —118 47 = corrected Tangent. (If corrected Fxt 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 +50 Tan.'=1 ..:18.47 '- --'• 7 = ° 192' .0 °. 543 S. C.=sta. 541-X53.53 11* 40,.= u . « �.. 543 } . L. C. __ 2 .33.33 86.86 E. C. — Sta. 543+86.86 100-53.53 =46.47 X3'(def. for l ft. of 10° Cur.)`=139.41' 2° 19''=def. for sta. 542. 9 Def; for 50 ft. =2° 30' for a 10° Curve. i + Def. for 36.86 ft. -1° 501' for a 10° Curve. oto - xr cc 1c o i 4 • } AS•