158 



SCIENCE. 



MOUNT HAMILTON, CAL. 

 We present our readers with a view of Mount Hamilton, 

 the site selected for the Lick Observatory. Previous to any 

 decision being finally arrived at, Mr. S. W. Burnham, of 

 Chicago, was directed to make a report upon the fitness of 

 the selection for the purpose. He states that "in accordance 

 with an arrangement made with the Trustees of the James 

 Lick bequest to make a series of astronomical observations 

 for the purpose of determining the atmospheric condition of 

 that location, with reference to its adaptation for the pro- 

 posed Lick Observatory (originally suggested by Prof. Ed- 

 ward S. Holden, in 1874, and subsequently approved by 

 Prof. Simon Newcomb, in 1879), I left Chicago on August 

 10, 1879, arrived in San Francisco on the evening of August 

 15, and left for Mt. Hamilton }he next morning in company 

 with Capt. Richard S. Floyd, President of the Trustees. 

 The summit was reached during the afternoon of the same 

 day. The telescope, which was already on the ground, was 

 hurriedly unpacked, temporarily set up in the observatory, 

 and used that night." 



SITUATION OF MT. HAMILTON. 



The city of San Jose, the nearest point of railroad con- 

 nection from Mt. Hamilton, is 50 miles south of San Fran- 

 cisco. Mt. Hamilton, by the highway, is 26 miles from 

 San Jose, nearly east, and is reached by a good road con- 

 structed two or three years since by the county of Santa 

 Clara. In order to keep the grade within the limit of six 

 feet in one hundred, the last portion of the road is carried 

 up the ridges of the mountain by a circuitous route. The 

 distance between the Observatory and San Jose, in an air- 

 line, is only 13 miles. 



The approximate geographical of the Observatory Peak 

 is: 



Longitude 121 36' 40" W. 



Latitude 37 21' 3" N. 



The elevation of this point is 4,250 feet above the level of 

 the sea. The north peak, which is about three-fourths of a 

 mile distant, is 140 feet higher. The ridge between is 

 a good trail connecting the two peaks. The sides of the 

 mountain, in most directions, are very steep, and form an 

 acute angle at the summit. The view from the peaks is 

 unobstructed in every direction, there being no higher 

 ground within a radius of 100 miles. In this connection the 

 e report of Messrs. Herrmann Bros., the engineers who 

 surveyed the road, will be of interest: 



"The scope of the horizon from Mt. Hamilton takes in 

 more ground, according to Prof. Whitney's judgment, than 

 almost any similar peak in the United States, there bein^ no 

 obstruction to the view from any quarter. It is remarkably 

 free from fogs and clouds, as we had ample occasion to ob- 

 serve during our last winter's stay on the mountain when 

 locating the road. The bearings of the most notable objects 

 are as follows, the distances being taken, when out of our 

 county, from our most reliable maps: 



Mt. I. oma Prieta ^-35° 5' VV., 19}^ miles. 



Mt. Thayer S. 51° .8' W., 19K " 



Mt. Poucher S. 38° 35' W., 6 



Jilock Mountain S. 87 W., aj% " 



Mt. Tamalpais N. 51 20' W., 66 " 



Mission Peak N. 47 55' W., 16 " 



Mt. Story N.25 45' W., ioJi " 



Mt. Uiablo N. 21 45' W., 3g ^ " 



Mt. Sautana S. 37 K., 35 " 



Murphy'i Peak S. 6° S ' W„ 15 



None of these points reach the altitude of Mt. Hamilton. 

 Of those within a radius of 20 miles the Loma Prieta reaches 

 3,800 feet, Thayer 3,550, and Block Mt. 2,800. All the rest 

 are between 1,500 and 2,500 feet. Of the further peaks Mt. 

 Diablo is 3,856. 



The formation of Mt. Hamilton, as of all the near sur- 

 rounding ridges, is of trap rock. The high points, not 

 worn down by the atmosphere and the action of the rain, 

 are, therefore, very hard as soon as the upper crust is re- 

 moved. In building the road we struck this hard rock at 

 six or seven points on and near the cone, with a good pros- 

 pect of finding it continuous and getting harder in the same 

 proportion in going deeper. It has broken through the 

 older formations at several points, near the base of the 

 mountain, where it shows the same character, only inten- 

 sified. At the top it appears as a greenstone porphyr, with 

 small larkspur veins, exceedingly hard, without any defined 

 strata, but in large boulders worn smooth, and generally 

 flat on one side, and cemented together by other material 

 less hard and easier to work. At a great many places the 

 metamorphic slate, uplifted by the later upheavals, shows 

 in considerable bodies, one of them being on the south side 

 of the Observatory Peak, and nearly opposite one of the 

 hardest points of porphyr." 



At sunset the Pacific Ocean is seen over the summit of 

 the Coast Range at various points, and occasionally a snow- 

 covered mountain was seen in a northerly direction, sup- 

 posed to be Lasson Butte, the distance of which is about 

 175 miles. The great range of the Sierra Nevada, about 

 130 miles distant, came out sharp and distinct at sunrise. 

 There were many very distant peaks in the east and south- 

 east which could not conveniently be identified. As an 

 illustration of the transparency of the atmosphere, I may 

 mention a fact communicated to me by Prof. Davidson, of 

 the U. S. Coast Survey. He was at work in the Sierra Ne- 

 vada, at an altitude of over 10,000 feet, and was able to see 

 with the naked eye the five-inch mirror of a heliotrope 175 

 miles distant. 



For a critical resumd of the work done by Mr. W. S. 

 Burnham upon Mount Hamilton, and the results he arrived 

 at, we refer our readers to the article on " Mountain Sites 

 for Astronomical Observatories," in our last week's issue. 



The opinion of Mr. Burnham is summed up in the 

 last words of his report when he observes that " Mount 

 Hamilton would be much more desirable, and more 

 could be accomplished there with a large telescope than 

 at any other place where an observatory has yet been 

 established. So far as there have been opportunities 

 for judging, it is obviously an appropriate place for 

 erecting and maintaining the telescope to be constructed 

 under the Lick deed of trust, and required to be " superior 

 to, and more powerful than, any telescope ever yet made." 

 With such an instrument in such a field wonderful discov- 

 eries may be made. The only limit to the size of the object 

 glass would be found in the mechanical difficulties attend- 

 ing its construction. No refractor that can be made in the 

 present state of the art would be unsuitable, so far as the 

 observed conditions would enable one to judge. It is im- 

 possible to overestimate the great discoveries which might 

 be made and the important work done with a first-class ob- 

 ject glass of thirty inches or more aperture, as perfect in all 

 respects as the instrument at the Naval Observatory at 

 Washington." 



