THE IMAGINARY RANGE AND TROUGH. 



45 



tions in the United States of America, which may be accepted as 

 not widely different from the average effect elsewhere, the next 

 stage in the investigation is to • calculate the result of supposing a 

 departure from these average conditions in one direction or another. 

 The first of these, to be considered, is a variation of the depth of 

 compensation, still supposed to be uniform throughout the depth to 

 which it extends, and the depths taken for calculation will be those 

 for which Mr. Hayford has given tables, namely 162-3 km. or about 

 100 miles and 798 km. or about 50 miles. 



In table No. 7, the result of calculation for these two depths is 

 given, to the nearest whole second of arc, as well as the deflections 

 resulting from Mr. Hayford's factors for uniform compensation 

 to a depth of 1137 km., or about 71 miles, and the differences 

 between these values. The meaning of these differences being 

 that, if the calculation had been made according to the Hayford 



Table 7. — Deflections which would be produced by the Imaginary 

 Range on the supposition oj uniform compensation to various 

 depths. 





Assumed Depth of Compensation. 



Station. 















1623 km. 



Diff. 



113-7 km. 



Diff. 

 + 3 



798 km. 



— 10 



— 13 



— 2 



— 11 



I 



1 _ 8 



— 9 



— 16 



— 3 



— 13 



-i 3 



! -10 



— 8 



— 18 



— 3 



— 15 



r 3 



— 12 



— 7 



— 20 



— 4 



— 16 



-r4 



— 12 



— 6 



— 21 



— 4 



— 17 



+ 4 



— 13 



— 5 



— 22 



— 4 



— 18 



+ 4 



— 14 



— 4 



— 23 



— 4 



— 19 



+ 4 



— 15 



- 3 



— 25 



— 5 



— 20 



+ 4 



— 15 



— 2 



— 26 



— 5 —21 



+ 4 



— 17 



- 1 



— 29 



— 5 — 24 



+ 4 



— 20 







— 58 



— 5 — 53 



+ 5 



— 48 



+ 1 



— 19 



— 4 —15 f :! 



-- 12 



+ 2 



— 11 



~ 2 — 9 



+ 3 



— 6 



+ 3 



7 



— 2 — 5 



+ 2 



- 3 



+ 4 



— 5 



— 2 — 3 



+ 1 



— 2 



+ 6 ! 



— 3 



-1 - 2 



+ 1 



— 1 



+ 6 



2 



— 1 — 1 



— 1 



+ 7 



— 1 



— 1 







+ 8 



— 1 



— 1 







+ 9 











o 







+ 10 











o 







[ 193 ] 



