Mineralogy and Geology. 423 
was made by a party of -_ ie 6 re of that place, three of whom 
gave out when near the summ ut the fourth, Edward Ayres, perse- 
vered ti succeeded in lar the topmost pinnacle,” which he repre- 
sents as a “bare, rugged crag only large enough to stand upon.” y 
found “a crater saints 3000 ft. below the top, from which a sulphurous 
smoke ascended.” 
The present year, we have more detailed accounts of two other ascents. 
The first of these was made on the 26th of July, when “a party from 
Portland reached the summit after six hours travelling from the snow 
in 
mond Tak a distance of 400 miles.” pbecr leap to the 1 maps, the act tual 
distance between these peaks is but 260 miles. ) 
n the 20th of last August, another ascent was made by six gentlemen, 
one of whom, Prof. Alphonso Wood, has a a detailed account of 
the trip before the California Academy of Natural Sciences at their meet- 
except where melted by hot gases and steam. “On the west side of the 
crater is still an open abyss whence issue constantly volumes of strongly 
sulphurous smoke. That there is heat there, is evident from the immense 
depression in the snow about the place,—depressed not less than a thou- 
sand feet below the snows which fill to the brim the other portions of the 
ancient crater.” He measured the various altitudes by observing the boil- 
ing point of water, and gives the following figures: “Summit of the Cas- 
cade Range and foot of Mt. Hood proper, 4,400 ft.; the limits of forest 
trees 9,000 ft.; highest limits of vegetation 11 000 ft.; summit of the 
SpA 17,600 fi.” The observed temperature of the boiling point he 
states at 180° F. on the summit, and a m that deduces the last figures 
quoted and = by anne that w = consider this the highest 
orth America. 
