SE Mountains in New York. 
measurement ; a discrepancy which cannot be attributed to any 
inaccuracy of adjustment in the instrument used by me, since if by 
any error in this respect, the angle of elevation was too great or too 
small in one case, it Was also too great or too small in the other, 
producing a corresponding elevation or depression in both. Nei- 
ther can it be attributed toa difference in the estimated allowance 
for refraction, for this allowance was the same in both cases; 
hence if too great or too small, the elevations of both were simi- 
larly affected and to the same amount. ‘The observations were 
also made from the same spot at nearly the same time of the same 
day ; hence there could probably be no great difference in the re- 
fractive power of the atmosphere, 
Again, so great a difference could not well result from an error 
in the distances, for although these were obtained as stated from 
the map, they were tested by comparing with known distances 
upon the same map, the latter having been projected on a large 
scale and compiled from actual surveys, with the positions of the 
several peaks, as is believed very accurately defined, that of Mt. 
Marcy in particular, coinciding very nearly with the location and 
bearing of it from Whiteface and other points, as described by 
Mr. Emmons. That some other peak was taken for Mt. Marcy, 
as is intimated by Mr. Emmons, is therefore scarcely possible, 
more especially as it is certain that the one observed was the 
highest of the group in which Mt. Marcy is situated. Had the 
peak in question been a lower instead of the highest one of the 
group, its not being “distinguishable” could be urged by Mr 
Emmons with more propriety. 
Assuming therefore, as is proper to do under these circumstal- 
ees, that the trigonometrical measurement exhibits very neatly 
the relative elevations of the high peaks in Vermont and New 
York, it follows, that to place Mr. Emmons’s barometrical meas 
urements of Whiteface and Mt. Marcy upon a par, as it regat 
accuracy, with the barometrical measurements of Camels Hump 
and Mansfield, that the former should be reduced, the first about 
290 and the second about 800 feet ; or in other words, these at@ 
the differences in the barometrical measurements by the two ob 
servers. Both surely cannot be correct ; and it is equally certaill 
also, that both may be incorrect. Until, therefore, Mr. ons 
shall have proved, that his measurements are entitled to a highet 
degree of confidence, he must submit to have their accuracy que 
