CALIFORNIA ACADEMY OF SCIENCES. 229 



NOTES ON MOUNT PITT. 

 By Arthur B. Emmons, Ph. D., LL. B. 



Read July 6th, 18S5. 



Scattered along the Cascade Range, from California through 

 Oregon and Washington Territory, are a number of extinct vol- 

 canoes, whose isolated snow-capped peaks tower high above the 

 rest of the range. They attain elevations from ten to fourteen 

 thousand feet and over; and in their simple grandeur add char- 

 acter to the country all about them. Several of these peaks, as 

 Mt. Hood, Mt. Shasta, and Mt. Rainier, are well known by name 

 far beyond the limits of the territory they overlook. 



One of the southernmost of these volcanoes is Mt. Pitt, which 

 is situated in the southwestern part of Oregon, about fifty miles 

 northeast from Jacksonville, and directly west of Upper Klam- 

 ath Lake. Although one of the lowest of these extinct volcanoes, 

 it had never been ascended before the summer of 1875, except 

 by one or two parties of prospectors; and nothing was known of 

 it further than that it was an extinct volcano — which knowledge, 

 however, was the result of observation from a distance, and not 

 the fruit of the ascents just mentioned. Last summer* its height 

 was determined with a barometer, and its geology made the sub- 

 ject of several weeks special study — the results of which are 

 given in this paper. 



The elevation of Mt. Pitt was found to be 9,663 feet above 

 Portland, Oregon, that is, 9,718 feet above the level of the sea. 

 A cistern barometer, one of Green's of New York, was used in 

 its determination. The height above Portland of our camp on 

 Four Mile Lake, which is on the summit of the Cascade Range, 

 northeast from Mt. Pitt, and just at its foot, was first determined 

 by a series of barometrical observations, extending over four or 

 five days, and referred to the synchronous observations made at 

 the office of the Signal Service, at Portland, as a base. The 



♦With the exception of the microscopical determination of the rocks, this paper was 

 prepared and written in the winter of 1875-6, but owing to press of other matters has only 

 now been finished. 



