I9I4] 



/. Arthur Harris and Ross Aiken Gortner 



263 



TABLE 2 

 A = 1.20° — A = 3.190° 



The form of Table i is familiär and seif explanatory. In Table 2, the first 

 place of decimals is given at the head of the column, while the second place is 

 given at the left. Between values for consecutive hundredths of degrees are 

 given the first difference. From the table the values are 636.98 for A 3=2.92° and 

 634.81 for A = 2.93°. By interpolation 1860/A for 2.926° = 636.98 — 2.17 X6/10 

 = 635.68, agreeing in this particular case exactly with the value calculated directly. 



