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_ 1 CURVE- TABLES. <br />Published by' KEUFFEL & ESSER CO. <br />: ' HOW TO USE "CURVE • TABLES. <br />-Table I.' contains Tangents and Externals to a'11 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 An le by the given Tangent. <br />'To find Deg. of Curve, having the Central Angle and .External: <br />Divide Ext. site 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. Tari. or Nat. Ex. Sec. <br />EXAMPLE. <br />Wanted a Curve with an Ext. of about 12 ft. Angle. <br />of Intersection or. I. P. =23° 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 10° 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 />Ang.23'20'=23.33 =10=2.3333=L. C. - <br />2° 191'= def. for sta. 542. 1 P.=sta. 542-72 <br />40 493' = " +50 Tan. = 1 .18.47 <br />70 193' = " " u 543 <br />9°4931= " " "+50 B. C.=sta., 541-x-53.53 _ <br />11° 40'=, a" " L. C.— 2_33.33 <br />86.86 E. C:=Sta. 543 -86.86 <br />100-53.53=46.47X3'(def. ford ft. of 10° Cur.)=139.41'= <br />2° 191' =def. for sta.-542. <br />- Def.'for 50 ft. =2° 30' fora 10° Curve. <br />Def. for 36.86 ft'. P 503' for a 10° Curve. <br />!x <br />I_ <br />_ 1 CURVE- TABLES. <br />Published by' KEUFFEL & ESSER CO. <br />: ' HOW TO USE "CURVE • TABLES. <br />-Table I.' contains Tangents and Externals to a'11 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 An le by the given Tangent. <br />'To find Deg. of Curve, having the Central Angle and .External: <br />Divide Ext. site 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. Tari. or Nat. Ex. Sec. <br />EXAMPLE. <br />Wanted a Curve with an Ext. of about 12 ft. Angle. <br />of Intersection or. I. P. =23° 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 10° 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 />Ang.23'20'=23.33 =10=2.3333=L. C. - <br />2° 191'= def. for sta. 542. 1 P.=sta. 542-72 <br />40 493' = " +50 Tan. = 1 .18.47 <br />70 193' = " " u 543 <br />9°4931= " " "+50 B. C.=sta., 541-x-53.53 _ <br />11° 40'=, a" " L. C.— 2_33.33 <br />86.86 E. C:=Sta. 543 -86.86 <br />100-53.53=46.47X3'(def. ford ft. of 10° Cur.)=139.41'= <br />2° 191' =def. for sta.-542. <br />- Def.'for 50 ft. =2° 30' fora 10° Curve. <br />Def. for 36.86 ft'. P 503' for a 10° Curve. <br />!x <br />