36-1 PROCEEDINGS OF THE CALIFORNIA 



Dr. Ayres remarked «n explosive sounds heard by him recently, 

 during perfectly clear weather, in the vicinity of Borax Lake. They 

 seemed to come from beneath the surface, and recalled the subter- 

 ranean explosions or noises mentioned in the Geology of California, 

 Vol. I, as having been heard in the vicinity of Mount Helena. 



Regular Meeting, September 16th, 1867. 

 Vice President Ransom in the chair. 



Twelve members present. 



Donation to the Cabinet : Twenty-eight mineralogical specimens 

 from Dr. A. B. Stout; mineralogical specimens from Mount Hood, 

 by Col. R. S. Williamson. 



The following paper was read : 



On the Height of Mt. Hood. 



BY K. 8. AVILLIAMSON. 



:» 



Having recently formed a party and visited Mt. Hood for the purpose of 

 ascertaining its altitude, and as my determination of its height is much less than 

 previous parties have made it, I think it proper to state somewhat in detail the 

 nature of the observations and the method I have pursued to arrive at the num- 

 ber I adopt as a close approximation to its true height. 



By the kindness of Gen. F. Steele, commanding the Department of the 

 Columbia, the necessary transportation was furnished for the party, consisting 

 of twelve persons, of whom my two assistants, Lieut. W. H. Heuer. U. S. 

 Engineers, and Mr. John T. Best, were specially charged with the observations 

 on the summit. We left Portland, Oregon, August 20th. and on the evening of 

 the twenty-second arrived at a place on the slope of the mountain, where we 

 camped, and from which, the next day, the ascent was made ; seven of the party 

 attempting to reach, and six reaching, the summit, where they remained from 

 one and a-half to three hours. 



From this camp to the summit and back ten hours were occupied, starting at 

 7:30, a.m. The weather was clear and pleasant, and had been so for several 

 days before, and was so for several days after. 



The instruments used at all the stations were made by James Green, of New 

 York, were in perfect order, and most of them new. They consisted of cistern 

 barometers reading to two thousandths of an inch, with attached thermometer, 

 and open air thermometer, (dry and wet) with large divisions, so that they were 



