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- - - CURVE TABLES. <br /> Published by KEUFFEL & 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,by dividing the Tan. <br /> - or Ext.o <br /> -------- ---- --- - pposite the given Central Angle by the given degree of curve. <br /> To find Deg, of Curve, having the Central Angle and Tangent: <br /> I <br /> Divide Tan. o--- -- - - -- -- — - pposite the given Central Angle by the given Tangent. <br /> To find Deg. of Curve, having the Central Angle and External: <br /> - _-- Divide Ext.opposite the given Central Angle by the given External. <br /> To find Nat.Tan.and Nat.Ex.Sec.for any angle by Table I.:Tan. <br /> or Ext,of twice the even angle divided by the radius of a 1 curve will <br /> - g� <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.=230 20' to the R. at Station <br /> - - 542+72. <br /> ---- -- Ext.in Tab. I opposite 230 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 F <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 /> 3 .r 9` 40 191'=def.forstta. 542 I. P.=sta. 542+72 <br /> _- _ a a a +50 Tan.= 1 .18.47 <br /> - _ - - 70 1911= a a a 543 B. C.=sta- 541 53.53 <br /> 1 f 90 49j'= a a a -�50 <br /> --- - <br /> 1I*40r a a a 543+ L. C.= 2 .33.33 <br /> =- <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 /> 2°19}'=def.for sta.542. <br /> Def.for 50 ft.=2°30'for a 10°Curve. <br /> Def.for 36.86 ft.=l°50j,'for a 10°Curve. <br /> x� <br /> 10• LPA-9..3-801E0� <br /> - - - Carvo <br /> -- - <br /> i <br />• . <br /> - d' <br /> • <br />