926 General Notes. [ November, 
THE GREAT ANDES OF THE Equator.—Mr. Edward Whymper 
has recently read a most interesting account of his journey in 
Ecuador before the Royal Geographical Society. It is given in 
full in the Proceedings for August. We have space here for only 
two extracts, the first relating to one of the principal objects of 
his journey ; the comparison of the working of aneroid against 
mercurial barometers at great elevations, and also the value of 
calculations based on the boiling point of water; and the second 
regarding the glaciers of the Ecuadorian Andes. To test the 
value of the aneroid barometer, Mr. Whymper took with him 
eight instruments carefully selected, after a trial of twelve months, 
from a number of ‘others. 
“Upon leaving England they were well together, the greatest 
difference between them being about the eighth of an inch, or 
more exactly, .13. The value of this difference at the level of 
the sea amounts to about 100 feet; and if the mean of the whole 
had been taken, there would have been an infinitesimal difference 
between it and the reading of a standard mercurial. But by the 
time I arrived at Guayaquil this difference had increased to .35; 
on arrival at Guaranda | 8900] it had still further risen to .74; at 
our first camp on Chimborazo [14,300] it had mounted to 88, 
and at our third camp [17,200] to 1.2 inch. These were the dif- 
at starting to the extent of 100 feet, and by the time we had 
risen to 17,000 feet, this difference had increased to about /w 
thousand feet. If you consider that these were not aneroids 
selected at random, but .were the pick of a number which had 
been expressly constructed for the journey, I think you will 
that this experiment conclusively demonstrated the uselessness of 
expecting to obtain absolute determinations of altitude from any 
number of aneroids ; and, expensive as the experience was, ! ©? 
not consider it dearly gained, as it decided that matter so far as I 
desire to pursue it, for once and all. The best of all ways to ah 
tle whether altitudes can be deduced with accuracy from the indi- 
cations afforded by the boiling-point of water, would of course 
be to conduct a series of experiments on the boiling-point at 
positions the height of which had been determined with scrupu- 
lous accuracy trigonometrically ; but the opportunities of doing 
» this at great elevations are not numerous, and such experiments 
can be performed at heights exceeding 16,000 feet in India alone. 
The next best way is to compare them against the mercurial barom- 
eter and, as we had mercurials almost always with us, took the 
opportunity to make experiments, with the result of finding that 
the boiling-point observations consistently yielded lower altitudes 
than the mercurial barometer, and I quote in illustration three 0 
_ the highest stations at which water was boiled, namely, the sum- 
mits of Cotopaxi, Antisana and Cayambe: : 
