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CURVE TABLES. <br /> a `? _. <br /> Published by KEUFFEL & WMR CO. <br /> HOW TO UM CURVE TABLES. <br /> Table I. contains Tangents and Externals to a 1'curve. Tan.and <br /> Ext.to any other radNentay be found nearly enough,by dividing theTan. <br /> or Ext.o polite the given tral An le b the Qiven degree of curve. <br /> --- - __ <br /> To find Deg. of Curve, having tFie entral Angle and Tangent: <br /> Divide Tan.opposite the given CenWil Auele by the given Tangent. <br /> To find Deg. of Curve, having the Central Angie and External: <br /> - - _- Divide Eat.o posite the given Central,Angle by the given External. <br /> To find Nat.Tap.and Nat.Ex.Sec,for any aaple by.Table I.:TwL <br /> -- -- or Ext.of twice the iven le divided by the radius of a 1'curve will <br /> be the Nat.Tah.or Nat.Ex.Bec. <br /> ---- --- — --- EXAMPLE. <br /> Wanted a Curve with an Ext.of about 12 ft. Anjle <br /> of Intersection or I. P.=23' 20' to the R. at Station <br /> 542-x-72. <br /> Est.in Tab.I opposite 23'20'-120.87 <br /> 1M.87+12-10.07. Say a 10°Curve. <br /> Tan.in Tab. I opp.23'20'=1183.1 <br /> - - ------- - - ------- <br /> 1183.1-1-10-118.31. <br /> Correction for A.23'20'for a 10'Cur.=0.16 <br /> - -= --- - - 118.31 x-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 /> 2'194'-def.for sta. 542 I. P.=sta. 542+72 <br /> __ _-_--{ ---_-�-- 4'49}1a « « « +50 Tan.= 1 .18.47 <br /> 7'19+}'_ « « « 543 <br /> - -- - --= ---- -- -- B.C.-sta. 541-}-53.53 <br /> ------ 9'491'_ « « « x-50 <br /> -- --- <br /> 11'40'- « « + L.C.= 2 33.33 <br /> i 86.86 E.C.=Sta. 543+" <br /> -- - ------ -- -- 100-53.53-46.47X3'(def.for 1 ft.of 10'Cur.}-139,41'w) <br /> 2'191'-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 /> .AngtE•t0•' <br /> - ___ ro•cww <br /> 1 <br /> t • <br /> air <br />