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- — s CURVE TABLES. <br /> Published by KEUFFEL 8i ESSER CO. <br /> _ HOW TO USE CURVE TABLES. <br /> Table I. contains Tangents and Externals to a 1°curve. Tan.and <br /> Ext.to or Ext.o y o opposite the oven Cen found tral Angnearly hem given degree curve. <br /> To find Deg. of Curve, having theeCentraVAngle�and Tangent: <br /> :Divide Tan.opposite f Curve haviniven gtthe Central <br /> le Athen le and Eiven xternal: <br /> To find De , <br /> - `Divide Ext. opposite the given Centtral Angle by the given External. <br /> - - To find Nat.Tan.and Nat.Ex.Sec.for any angle by Table L:Tan. <br /> or Ext.of twice the gg��vwA an le divided by the radius of a V curve will i <br /> i <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 1. 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 ab.13-10=118.31. 1183.1 <br /> �. <br /> Correction for A.23°20'for a 10°Cur.=0.16 <br /> � — <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°19Y=def.for sta. 542 I. P.=sta. 542 -72 <br /> 4049x'= " " " +50 Tan.= 1 .18.47 <br /> 7019 1__ " " " 543 <br /> — 9049j'= " " a +50 B.C.=sta. 541 -53.53 <br /> 11°40'= a a a 543+ L.C.= 2 .33.33 <br /> 86.86 E.C.=Sta. 543+86.86 <br /> _ 100-53.53=46.47X31(def,for 1 ft.of 10°Cur.)=139.41'= <br /> 2°19)'=def.for sta.542. <br /> j - Def,for 50 ft.=2'30'for a 10°Curve. <br /> Def,for 36.86 ft.=1°50+)'for a 10°Curve. <br /> t* <br /> >s <br /> V a4> <br /> { <br /> 10•Cure. <br /> 4 <br /> 0 <br /> . t <br />