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SCIENCE. 



[N. S. Vol. VII. No. 167. 



ductive science was due to the necessities 

 of deductive science, and the greatest de- 

 velopment of the former has come from 

 the trial of hypotheses belonging in the 

 borderland between science and philosophy. 



My effort this evening is to show that 

 discoveries, which have proved all-impor- 

 tant in secondary results, did not burst 

 forth full-grown ; that in each case they 

 were, so to say, the crown of a structure 

 reared painfully and noiselessly by men in- 

 diiferent to this woi-ld's affairs, caring little 

 for fame and even less for wealth. Facts 

 were gathered, principles were discovered, 

 each falling into its own place until at last 

 the brilliant crown shone out and the world 

 thought it saw a miracle. 



This done, I shall endeavor to draw a 

 moral, which it is hoped will be found 

 worthy of consideration. 



The heavenly bodies were objects of 

 adoration from the earliest antiquity ; 

 they were guides to caravans on the desert 

 as well as to mariners far from land ; they 

 marked the beginning of seasons or, as in 

 Egypt, the limits of vast periods embracing 

 many hundreds of years. Maps were made 

 thousands of years ago showing tbeir posi- 

 tions ; the path of the sun was determined 

 rudely ; the influence of the sun and moon 

 upon the earth was recognized in some de- 

 gree and their influence upon man was in- 

 ferred. Beyond these matters, man, with 

 unaided vision and with knowledge of only 

 elementary mathematics, could not go. 



Mathematical investigations by Arabian 

 students prepared the means by which, 

 after Europe's revival of learning, one, 

 without wealth, gave a new life to as- 

 tronomy. Copernicus, early trained in 

 mathematics, during the last thirty years 

 of his life spent the hours, stolen from his 

 work as a clerk and charity physician, 

 in mathematical and astronomical studies, 

 which led him to reject the complex Ptole- 

 maic system and to accept, in modified 



form, that bearing the name of Pythagoras. 

 Tycho Brahe followed. A mere star-gazer 

 at first, he became an earnest student, im- 

 proved the instruments employed, and 

 finally secured recognition from his sov- 

 ereign. For twenty-five years he sought 

 facts, disregarding none, but seldom recog- 

 nizing economic importance in any. His 

 associate, Kepler, profiting by his training 

 under Brahe, carried the work far bej'ond 

 that of his predecessors — and this in spite 

 of disease, domestic sorrows and only too 

 frequent experience of abject poverty. He 

 divested the Copernican hypothesis of 

 many crudities and discovered the laws 

 which have been utilized by astronomers in 

 all phases of their work. He ascertained 

 the causes of the tides, with the aid of the 

 newly invented telescope made studies of 

 eclipses and occultations and just missed 

 discovering the law of gravitation. He 

 laid the foundation for practical application 

 of astronomj' to every- day life. 



In the ISth century astronomy was recog- 

 nized by governments as no longer of 

 merely curious interest and its students re- 

 ceived abundant aid. The improvement of 

 the telescope, the discovery of the law of 

 gravitation and the invention of logarithms 

 had made possible the notable advances 

 marking the close of the 17th century. 

 The increasing requirements of accuracy 

 led to exactness in the manufacture of in- 

 struments, to calculation and recalculation 

 of tables, to long expeditions for testing 

 methods as well as conclusions, until finally 

 the suggestion of Copernicus, the physician, 

 and of Kepler, the ill-fed invalid, became 

 fact, and astronomical results were utilized 

 to the advantage of mankind. The voyager 

 on the ocean and the agriculturist on land 

 alike reap benefit from the accumulated 

 observations of three centuries, though they 

 know nothing of the principles or of the 

 laborers by whom the principles were dis- 

 covered. The regulation of chronom- 



