72 USE OF TABLES AT END OF WORK. 



Let H = '97169 ; required the value of t? 



H = -97169 

 Nearest below = -97 162 t=l\55 



101)7000(69 t= 1-55069 Answer. 



606 



940 

 909 



31 



The Table II. is used in exactly the same way, except 

 towards the end,, from t = 3*40 upwards ; in which 

 case the cipher at the end of t must be neglected, and only 

 one decimal place taken out of the table in the value 

 of t. For instance, to find the value of t answering to 

 K = -98222. 



K= -98222 

 Next below -98176 t=3-5 



306)46000(150 t = 3'5150 

 306 



1540 

 1530 



100 



In the first table, there is another result which will 

 frequently be wanted, and which I shall call H'. It 

 arises from adding half the second difference to the first 

 difference*, if the value of t be in the tables, and 

 making five decimal places. But if the value of t be 

 not in the tables, then H' must be formed for the 

 values of t immediately above and below ; and by means 

 of the first and the difference of the two, H' must be 

 found in exactly the same manner as H is found in 

 the first of the preceding rules, page 70., remembering 

 to subtract at the last step instead of adding, if the second 

 H' thus previously determined be less than the first. 



* Meaning the whole differences ; not the parts which precede the blank 

 space, as in the preceding rules. 



