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- CURVE TABLES. <br /> ---lee 2-4;3Published by KEUFFEL ESSER CO. <br /> HOW TO USE CURVE TABLES. <br /> t A r Table I. contains Tangents and Externals to a 1°curve. Tan.and <br /> - —'7 ---- - Ext.to any other radius may be found nearly enough,by dividing the Tan. <br /> -- --- ---- --- <br /> e or Ext.opposite the given Central An le by the given degree of curve. <br /> -- y - - - _ ____ _ To find Deg. of Curve, having the Central Angle and Tangent. <br /> y g 6 Divide Tan. opposite the given Central Angle by the given Tangent. <br /> To find Deg. of Curve, having the Central Angle and External: <br /> --/� •J, o ,r � _ Divide Ext. opposite the given Central Angle by the <br /> given External <br /> ---------- <br /> To find Nat.Tan.and Nat.Ex.Sec,for any angle by Table I.•Tan. <br /> / 3 - - --- --- - 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 /> / 3 0' - of Intersection or I. P.=23° 20' to the R. at Station <br /> .9 542+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 /> !>y4X - <br /> (If <br /> ___ _ _-_.._-_-__ —_ 118.31•- 0.16=118.47=corrected Tangent. <br /> corrected Ext is re uired find in same way) <br /> --- _ <br /> 3, i! - - - --- Ang.23°20'=23.33 =10=2.3333-L.C. <br /> 7' 1L 2°19F=def.for sta. 542 I. P.=sta.• 542+72 <br /> / 40 49j'= " " " +50 Tan.= 1 18.47 <br /> 3 6 J 7°i 191'= a cc 543 C.543 _sta. 541+53.53 <br /> > - - _- -- ---- - - - 110 40'= CC " 54+35-0- L.C.= 2 .33.33 <br /> o <br /> 86.86 E.C.=Sta. 543+86.86 <br /> 100-53.53=46.47X3'(def.for 1 ft.of 10°Cur.)=139.41'= <br /> _11 2°191'=def.for sta.542. <br /> Def,for 50 ft.=2°30'for a 10°Curve. <br /> - --------- <br /> Def.for 36.86 ft.=1°50+1'for a 10°Curve. <br /> -=_ <br /> 4-71 <br /> 1 7 <br /> >A <br /> 3 9� � LP.An9.23'YO• <br /> J pets dYj <br /> _ - ------ <br /> 3 7 10.carve q <br /> - ------ <br /> t <br /> R . . <br /> r <br /> V . <br /> • <br /> 1 <br />