7 68 Col. roy’s Experiments for 
him feems to make it, both parallaxes and refractions, 
will require correction. 
Upon the whole, though I wifhed to be concife in the 
recital of the experiments and obfervations contained in 
this paper, yet I found it neceflary at the fame time to be 
explicit. Some of them were either entirely new, or ma- 
naged in a different manner from what they had for- 
merly been. This forced me into a comparifon of many 
minute circumftances attending the operations, and to a 
tedious, though neceflary, combination of the various 
refults. Without taking a comprehenfive view of the 
whole matter, and ftating every thing with fairnefs and 
candour, I could not convey to others the ideas I enter- 
tained of it myfelf; nor enable them to judge, how far I 
had been juft in the conclufions already drawn, or con- 
fiftent in my fuppofitions concerning fucli points as are 
yet left doubtful. If I have been obliged to differ from 
Mr. de luc, it is becaufe the Bri'tifli obfervations, as well 
as his own (confidered by their extremes) feem to autho- 
rize it: he is himfelf too candid to fuppofe, that I have 
had criticifm in view, or indeed any other objeeft, than 
that of contributing my mite towards the difeovery of 
the truth, from the very good foundation which he hath 
already laid for it. I am aware it may be alledged, that 
I have rendered the theory of meafuring heights by 
c the 
