842 THE POPULAR SCIENCE MONTHLY. 



might be called self-educated, lie was not, as Mr. Barton shows, 

 wholly without assistance in pursuing his studies, although some 

 writers had mistakenly affirmed this, but that assistance was 

 small. Dr. Rush assumed, in the eulogy he pronounced upon 

 him, that the eminence he attained was to be ascribed " chiefly to 

 his having escaped the pernicious influence of monkish learning 

 upon his mind in early life"; otherwise, "instead of revolving 

 through life in a planetary orbit," he might have spent his time 

 "in composing syllogisms, or in measuring the feet of Greak and 

 Latin poetry." He understood the German and Low Dutch lan- 

 guages, acquired a reading knowledge of French, and " overcame 

 in a great degree the difficulties of the Latin tongue." He was a 

 firm believer in the Christian religion, though he was not at- 

 tached to any church. That speculative disquisitions were of 

 little interest to him is shown, perhaps, as much as by anything, 

 by his remark concerning a conversation with a clerical gentle- 

 man, that it was " not, perhaps, greatly to the satisfaction of either 

 of us ; for he appears to be a mystical philosopher, and I, you 

 know, care not a farthing for anything but sober certainty in 

 philosophy." He published but little, because, as his biographer 

 believes, he was too busy with work to give his time to the com- 

 position of formal papers. The list of his contributions to the 

 American Philosophical Society includes twenty-two titles of 

 papers relating to his orrery ; the transits of Venus and Mercury ; 

 the comet of 1770 ; a method of deducing the true time of the 

 sun's passing the meridian ; the difference of longitude between 

 the observations of ISTorriton and Philadelphia ; an explanation 

 of an optical deception; experiments on magnetism; a remark- 

 able meteor seen in 1779 ; a comet observed in 1784 ; a new method 

 of placing the meridian mark ; an optical problem ; astronomical 

 observations (on the Georgium Sidus and a transit of Mercury) ; 

 an account of several houses struck with lightning ; another ac- 

 count of the effects of a stroke of lightning ; several astronomical 

 observations described in a single paper ; a mathematical prob- 

 lem; a comet observed in 1793; the improvement of time-keep- 

 ers ; the expansion of wood by heat ; a problem in logarithms ; 

 and the mode of determining the true place of a planet in an 

 elliptical orbit his last paper, read February 5, 1796. To these 

 is added his oration on " Astronomy," delivered before the Ameri- 

 can Philosophical Society, on the 24th of February, 1775, and in- 

 scribed " To the delegates of the thirteen United Colonies." In this 

 oration, three years before the announcement of Mayer's discovery 

 of the proper motion of certain stars, and six years before Her- 

 schel's discovery of Uranus, the author put forth the suggestion, 

 which has since proved a presage, that the fixed stars, and par- 

 ticularly the milky way, would afford fruitful fields of observation. 



