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FI Lo 00 37 <br /> CURVE TABLES. <br /> Published by KEUFFEL 8s ESSER CO. <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,bydividing theTan. <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 /> "7' ---- -- ----- ----- — Divide Ext.o <br /> p R.iso v pposite the given Central Angle by the given External. <br /> To find Nat.Tan.and Nat.Ex.Sec.for any angle b Table I.:Tan. <br /> y <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. <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 /> --- -- -- <br /> _ - - - 542+72. , <br /> Ext.in Tab. I opposite 23°20•=120.87 <br /> --- - <br /> 120.87=12=10.07. Say a 10°Curve. <br /> AV' 114 7 ,7 Tan.in Tab. I opp.23°20'=1183.1 <br /> t' ?` _ [,� o -_ 1183.1- 10=118.31. <br /> _sT 7._ -_ i7 X9 Correction for A.23°20'for a 10°Cur.=0.16 <br /> 118.31+0.16=118.47=corrected Tangent. <br /> .Z_$7 (If corrected Ext.is required find in same way) <br /> /7 Ang.23°20'=23.33°=10=2:3333=L. C. <br /> 4_34_ _ _ _• .-�t� •/l e f - 2°191'=def.for sta. 542 I. P.=sta. 542+72 <br /> -/7 4°493'= " " +50 Tan.= 1 .18.47 <br /> --- <br /> �3 7°19 z'_ <br /> 90 4911 <br /> - B.C.=sta. 541+53.53 <br /> 8s�a-a �.-s �__� z'� - ----�Z �S - 11°40'= " " « 543+ L. C.= 2 .33.33 <br /> 86.86 E.C.=Sta. 543+86.86 <br /> \'V �.- L_ 100_53.53=46.47X3'(def,for 1 ft.of 10°Cur.)=139.41'= <br /> 7 y'7 2°192'=def.for sta.542. <br /> Def.for 50 ft.=2°30'for a 10°Curve, i s <br /> ---�— ------- 57 9 o 7 s7s = Def.for 36.86 ft. 1*50F for a 10°Curve. 9 <br /> I,RAn9.23°201 G•� <br /> ' y <br />