50 STATISTICAL METHODS. 



Example. Find the log tan of 52' 35". 



add (q - T) 4.685609 



52' 35" = (3120" + 35") = 3155" log 3.498999 



' ' t I) ' 



Ans. log tan 8. 184608 



To find the log cotangent of an angle less than 

 2 given to seconds. Take from the column headed ( q-\- Z) 

 the logarithm corresponding to the given angle, interpolating 

 for the last figure if necessary, and from this subtract the loga- 

 rithm of the number of seconds in the given angle. 



Example. Find the log cotan of 1 44' 22". 5. 



g + I 15.314292 

 6240" + 22". 5 = 6262.5 log 3.796748 



Ans. 11.517544 



These two pages may be used in the same way when the 

 given angle lies between 88 and 92, or between 178 and 180; 

 but if the number of degrees be found at the bottom of the page, 

 the title of each column will be found there also; and if the 

 number of degrees be found on the right hand side of the page, 

 the number of minutes must be found In the right hand col- 

 umn, and since here the minutes increase upward, the number 

 of seconds on the same line in the first column must be 'dimin- 

 ished by the odd seconds in the given angle to obtain the num- 

 ber whose logarithm Is to be used with (q I) taken from the 

 table. 



Example. Find the log cos of 88 41' 12". 5 



(q - I) 4.685537 

 4740" - 12*.5 = 4727.5 log 3.674631 



Ans. 8.360168 

 Example. Find the log tan of 90 30' 50". 



q+l 15.314413 



1800" + 50" == 1850' log 3.267172 



Ans. 12.047241 



To find the arc corresponding to a given log 

 sin, cos, tan, or cotan which falls within the 

 limits of the first two pages of Table X. 



Find in the proper column two consecutive logarithms be- 

 tween which the given logarithm falls. If the title of the 

 given function is found at the top of that column read the 



