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ea2 <br />{' <br />�>���;0•_$l9.Ga. <br />s� <br />i <br />� ��y�1d�i' <br />897. <br />II - <br />pa ZA <br />-i <br />—Q.�i'sem.', <br />Jt &Q <br />1���, f&-,, $6.7Z' l% <br />�J <br />TC>c' <br />a%lycj <br />S <br />; <br />%,3 . 9.��o <br />.8 o?s, 30 <br />q <br />( / } n o <br />�t 3 <br />�✓ <br />?. <br />ra. 36 <br />—.� <br />C4 <br />4011 <br />' <br />cv S <br />/'Q <br />yrs,$,`VT ' <br />, <br />-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 maybe found nearly enough, by dividing the Tan. <br />or Ext. opposite the given Central Angle by the given degree o1 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 />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 given angle divided by the radius of a 1° curve will <br />-be the Nat. Tan. or Nat. Ex..See. <br />EXAMPLE <br />Wanted a Curve with an Ext. of about. 12 [t. Angle <br />of Intersection or L P. =23° 20' to the R. at Station <br />542+72. <br />L:xt. in Tab. I opposite 23° 20' =120.87 <br />120.87=12='10.Q7. 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 />118.31+0.16 =118.47 =corrected Tangent. <br />,+ (If corrected F.'xt. is.required find in sauce way) <br />Ang. 23°20'=23.33°=10=2.3333=L. C. <br />2° 19' I'= fnrsta.• 542 1. P. —sta. 542+72 <br />4° 49z' = +50 Tan. = 1 .18.47 <br />�° 4911= <br />2 = « N 593 B. C. =sta. 541+53.53 <br />+50. 1 C. _ •2 .33.33 <br />110 40'= " 543'- <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 />7 2° l92'=def. for sta. 542. <br />Def. for 50 It. =2° 30' for a 10` Curve. <br />Def. for 36.86 it.. =1° 50;' for a 10° Curve. <br />