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CURVE TABLES. <br /> ---__--- --- -- --— ----- Published by KEUFFM & EMR CO. <br /> How TO USE CURVE TABLES. <br /> Table I. contains Tanggnts and Externals to a 1°curve. Tan.and <br /> -- -- --- - - ------- -- Ezt.to any other radius may be f ound nearly enough,by dividing theTan. <br /> or Ext.opposite the given Central An le by theg�"ven degree of curve. <br /> ---- -'— - —---- To find Deg.of Curve, having the Central Angle and Tangent: <br /> Divide Tan.opposite the given Central Angle by the given Tangent. <br /> Divide.Ext To find Deg. of Curve, having the Central Angle and External: <br /> polite the given Central Angle by the given External. <br /> To find Nat.Taa.and Nat.Ex.Sec.for any angle by Table I.:Tan. <br /> -- - — -- — or Ext.of twice the "vea aagle divided by the radius of a V curve will <br /> --- -- - gi <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 Starion <br /> - - --- --- ---- 542+72. <br /> Ext.in Tab.Iopposite 230 201—120.87 <br /> f — _ - --- 120.87+12=10.07. Say a 10°Curve. <br /> i 3 Tan.in Tab. I opp.23°20'=1183.1 <br /> i ?;7---- 1183.1+10"118.31. <br /> -- <br /> -` Correction for A.23°20'for a 10°Cur.=0.16 <br /> 2 118.31+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°19F-def.for sta. 542 I. P.=sta. 542+72 <br /> 4°49i'= a a ■ +50 Tan.= 1 .18.47 <br /> 7 -- 7°19},= a a e 543 <br /> B.C.=sta. 541+53.53 <br /> 9°491' +50 <br /> --- - +, L.C.= 2 .33.33 <br /> _ 86.86 E.C.-Sta. 543+86.86 <br /> 100-53.53-46.47 X3'(def.for 1 ft.of 10°Cur.)-139.4l'-, <br /> 2°19.1'=def.for sta..542. <br /> Def.for 50 ft.=2°30'for a 10°Curve. <br /> ---- - - Def.for 36.86 ft.-1°50}'for a 10°Curve. <br /> •x <br /> N <br /> lo•Curve <br /> 4 <br /> ' , lot <br />