MOUNTAIN OBSERVATORIES. 389 



grows with the power of the instrument. Atmospheric troubles are 

 magnified neither more nor less than the objects viewed across them. 

 Thus, Lord Rosse's giant reflector possesses — nominally — a magnify- 

 ing power of 6,000 ; that is to say, it can reduce the apparent dis- 

 tances of the heavenly bodies to -g-oVo" their actual amount. The moon, 

 for example, which is in reality separated from the earth's surface by 

 an interval of about two hundred and thirty-four thousand miles, is 

 shown as if removed only thirty-nine miles. Unfortunately, however, 

 in theory only. Professor Newcomb compares the sight obtained un- 

 der such circumstances to a glimpse through several yards of running 

 water, and doubts whether our satellite has ever been seen to such ad- 

 vantage as it would be if brought — substantially, not merely optically 

 — within five hundred miles of the unassisted eye.* 



Must, then, all the glowing triumphs of the optician's skill be coun- 

 teracted by this plague of moving air ? Can nothing be done to get rid 

 of, or render it less obnoxious ? Or is this an ultimate barrier, set up 

 by Nature herself, to stop the way of astronomical progress ? Much 

 depends upon the answer — more than can, in a few words, be easily 

 made to appear ; but there is fortunately reason to believe that it will, 

 on the whole, prove favorable to human ingenuity, and the rapid ad- 

 vance of human knowledge on the noblest subject with which it is or 

 ever can be conversant. 



The one obvious way of meeting atmospheric impediments is to 

 leave part of the impeding atmosphere behind ; and this the rugged 

 shell of our planet offers ample means of doing. Whether the advan- 

 tages derived from increased altitudes will outweigh the practical diffi- 

 culties attending such a system of observation when conducted on a 

 great scale, has yet to be decided. The experiment, however, is now 

 about to be tried simultaneously in several parts of the globe. 



By far the most considerable of these experiments is that of the 

 "Lick Observatory." Its founder was from the first determined that 

 the powers of his great telescope should, as little as possible, be fet- 

 tered by the hostility of the elements. The choice of its local habita- 

 tion was, accordingly, a matter of grave deliberation to him for some 

 time previous to his death. Although close upon his eightieth year, 

 he himself spent a night upon the summit of Mount St. Helena, with 

 a view to testing its astronomical capabilities, and a site already se- 

 cured in the Sierra Nevada was abandoned on the ground of climatic 

 disqualifications. Finally, one of the culminating peaks of the Coast 

 Range, elevated 4,440 feet above the sea, was fixed upon. Situated 

 about fifty miles southeast of San Francisco, Mount Hamilton lies far 

 enough inland to escape the sea-fog, which only on the rarest occasions 

 drifts upward to its triple crest. All through the summer the sky 

 above it is limpid and cloudless ; and, though winter storms are fre- 

 quent, their raging is not without highly available lucid intervals. As 



* " Popular Astronomy," p. 145. 



