THE FUNCTION OF LAKGE TELESCOPES. 125 



appreciation. And it must be admitted that this demand on the part 

 of some portion of the public press, while in one sense only a certain 

 phase of the almost universal desire for sensation, has not lacked 

 encouragement from men who are generally regarded as serious 

 astronomers, intent on arriving at the truth by the methods of exact 

 science. To such is due a widespread belief in the inhabitants of Mars, 

 who in the popular novels of the day have not even been content with 

 life upon their own planet, but, in accordance with the astrological sig- 

 nificance of the god of war, have come to bring destruction upon the 

 inhabitants of the earth. However entertaining we may find the doings 

 of these strange individuals, whether at home or abroad, we must not 

 make the mistake of classing the works which describe them with the 

 literature of science, but rather accord them their proper place among 

 the pleasant romances which we owe to men of letters. 



I can not better illustrate one phase of this pseudoscience than by a 

 reference to the celebrated "Moon Hoax," which caused such a stir at 

 the time of its appearance. When Sir John Herschel sailed for the 

 Cape of Good Hope in 1833 he little imagined what marvelous discov- 

 eries lay before him. It is true that he was provided with a great 

 reflecting telescope of 20 feet focal length, which was to be used upon 

 the previously unexplored regions of the southern heavens, and it 

 could not have been difficult for him to form some conception of the 

 valuable additions he was certain to make to astronomical knowledge. 

 But the imagination of others by far outran the more prosaic course of 

 his own mind, and results were obtained for him which unfortunately 

 his telescope never served to show. Many who are present are no 

 doubt familiar with a pamphlet entitled Great Astronomical Discoveries 

 lately made by Sir John Herschel, LL. D., F. R. S., etc., at the Cape of 

 Good Hope, which was "first published in the New York Sun, from 

 the supplement to the Edinburgh Journal of Science." In the truly 

 entertaining pages of this ingenious narrative we find an example 

 which certain reporters of our own day seem to have taken to heart. 

 Let me quote a paragraph of nonsense which is so amusingly conceived 

 and proved so effective when published that one is almost ready to 

 forgive the perpetrator. After a lucid historical discourse ou the great 

 telescopes which had been made by Sir William Herschel and other 

 previous investigators, followed by an imj)assioned paragraph which 

 may well be considered to approach in eloquence the most fervid 

 astronomical literature of our own day, our author treats us to an 

 account of a conversational discussion between Sir John Herschel and 

 Sir David Brewster, which began with a consideration of certain sug- 

 gested improvements in reflecting telescopes, and soon directed itself 

 "to that all-invincible enemy, the paucity of light iu powerful magni- 

 fiers. After a few moments 7 silent thought, Sir John diffidently inquired 

 whether it would not be possible to effect a transfusion of artificial 

 light through the focal object of vision ! Sir David, somewhat startled 



