570 JOHN F. HAYFORD 
tations of a reduction in an assumed completeness and a reduction 
in depth. 
6. That in a computation such as that being criticized, based 
upon 733 stations all utilized fully in a single computation, though 
an error of moderate size in assumed completeness of compensation 
will produce residuals at the separate stations, it will have an 
exceedingly small, probably inappreciable, effect on the computed 
depth of compensation. 
7. That the residuals from the computation actually made, 
which residuals are printed in detail, show that the assumptions 
are in very close agreement with the truth, and especially that it 
is impossible that there is any large error in the assumed complete- 
ness of compensation. 
8. Finally by following the clues indicated in (4) it would be 
noted that if it were a fact that the actual depth of compensation 
is much less than 113.7 km. and the compensation much less than 
complete the residuals of the accepted final computation would 
show a certain systematic geographic distribution. For example, 
all longitude stations and all azimuth stations situated on or very 
near the Pacific coast, like Point Arena, should have residuals of 
the same sign as Point Arena. The geographic distribution of 
residuals which would be so produced does not exist. 
In short, if Mr. Lewis had carefully examined the evidence 
available to him, following logically the lines of thought on which 
he started, he would have reached the conclusion that an error of 
moderate size In assumed completeness of compensation would 
produce no appreciable error in the depth of compensation as 
actually computed, and that the actual compensation certainly 
departs but little from completeness. 
It should be clear from what is here printed that the alleged 
error 1n Hayford’s method of computation on which Mr. Lewis’ 
whole criticism rests is fictitious. Even if it is not clear to one 
who reads this very brief statement, it will certainly become 
perfectly clear to those who will examine the methods in detail 
with the numerical values before them. 
= Consult illustrations 5 and 6 of the Supplementary Investigation of the Figure of 
the Earth and Isostasy. 
