1842.] 



Compendious Logarithmic Tables. 



41 



The inverse use is not so convenient. 

 Given Log. 53087 Reqd.Nura. 



Tab. Log. next less 53020 N.N. 339 



67 



Prl.pt. (corrd.) next less 64 5 



3 



2-6 



part should be 64, being the mean 

 of 65 and 63 : which would agree 

 better with the result given by 

 the larger Tables. 



Number Reqd. 33952 



The Antilogarithmic Table contains the numbers to a series of 

 Logarithms from to 999. The first column contains the two first 

 figures of the Logarithm, the third being found at the top of the 

 columns ; and in the body of the Table is found the corresponding 

 natural number. When the Logarithm consists of more than 3 figures, 

 the proportional part for the 4th and subsequent figures, taken in the same 

 line, are to be added to the number given in the body of the Table. 



[The proportional parts being given for the mean difference at 

 the middle of the line, may be adjusted, if need be, to their proper 

 value, by allowing at sight for the difference between their value in that 

 and the next line, according to the distance of the 3rd and following 

 figures from 45 the middle of the line.] 



Example. 



Required the Number to Log. 71572. 

 For Log. 715 the Table gives, 60954 

 for 7 Propl. part is .... 98 

 for 2 Propl. part is 2*8 



Here the 3rd and subsequent 

 figures being close to the middle 

 of the line need no correction. 



610548 



Inversely Required the Logarithm to Number 61055. 

 Given Number 61055 

 Table Number next less . . 60954 The Logarithm is 715 



Difference 101 

 For difference next less 98 Proportional part is 7 



For difference next less 2*8 Proportional part is 2 



Log. Required, 71572 



