Latitude. 



Longitude. 



Elevation. 



Gravity. 



*( + )• 



M + ). 



h. g 



(dynes.) 



38° 53' 20" 



77° 1' 35" 



34 ft. 



980-100 



3V 20 25 



121 38 35 



4205 



979-651 



21 18 3 



157 51 46 



20 



978-936 



21 16 25 



157 50 1 



10 



978922 



20 2 25 



155 49 36 



8 



97S803 



19 42 32 



155 27 53 



6660 



978-490 



256 Scientific Intelligence. 



II. Teerestrial Physics. 



1. Gravity Determinations at the Sandwich .Islands, by E. U. 

 Preston (in a letter to J. D. Dana, dated Washington, Jan. 27). 

 — We have just completed the reductions of the gravity work 

 executed recently in the Hawaiian Islands. I have shown them 

 to Dr. Mendenhall and with his permission send the following 

 statement in regard to the results. The stations included in the 

 series are as follows: 



Washington Smithsonian Inst. 



Mt. Hamilton Lick Observatory 



Honolulu Kapuaiwa Building 



"Waikiki J. F. Brown's 



Kawaihae S. Parker's 



Kalaieha Humuula 



Mauna Kea Waiau 19 49 11 155 28 48 13060 978060 



From the above figures for gravity at the three stations on 

 Hawaii, it appears that the lower half of Mauna Kea is of a very 

 much greater density than the upper. The former gives a value 

 of 3'7 and the latter 2*1, the mean density of the whole mountain 

 being 2*9. This is somewhat greater than that found for Halea- 

 kala and is notably larger than the density of the surface rocks. 

 Indeed this appears to be the highest value yet deduced from 

 pendulum work, as we see by the following comparison : 



Mauna Kea 2 -9 



Fujinoyama 2-1 



Haleakala 2-7 



St. Helena 1-9. 



Ascension 1-6 



In view of this large value it is probably worth while to remark 

 that it depends on observations of Dr. Mendenhall's new half- 

 second pendulums — which attain a degree of accuracy hitherto 

 uuapproached in work of this kind. 



In regard to the above Dr. Mendenhall writes (Feb. 2, 1893): 

 I have been very much interested in Mr. Preston's determina- 

 tion of the density of the volcano Mauna Kea, relative to which, 

 as you will see, he has reached what seems to me to be a most 

 remarkable conclusion. When a few weeks ago he brought me 

 the results of his observations which showed a density for the 

 lower half of this mountain, of three and seven-tenths, being- 

 greater than that of diamond and, in fact, much greater than that 

 of any ordinary rock, it seemed to me that there must be an error 

 at some point of the reduction of the observations. I therefore 

 requested him to check the entire computation and it has been 

 gone over by two different computers, resulting in the discovery 



