818 THE POPULAR SCIENCE MONTHLY. 



service to astronomical science as calculators. What a number of 

 names we might cite of those who have given their time to the 

 collection of observations and determining the courses which com- 

 ets and the minor planets describe in space ! The positions of 

 three hundred thousand stars are now known; one third of the 

 work of determining them has been done by volunteer astrono- 

 mers. The famous catalogues of stars to which we have recourse 

 in official observatories have been prepared in the private obser- 

 vatories of Wrottesley, Hartnup, and Groombridge. To produce 

 such results, how great must have been the zeal and devotion of 

 those amateurs who, after numerous years of watching, have been 

 able to get together thousands of observations, with no reward ex- 

 cept the personal satisfaction of having been serviceable to astron- 

 omy ! Such labors, which are of the most ungrateful kind, and to 

 which professional astronomers devote themselves, have no im- 

 mediate result. The glory and fame which the discovery of a 

 comet or a planet brings at once to its author are not to be found 

 in them. They serve for the preparation of material which it is 

 certain can not be productive for ages to come ; for it is only then 

 that these catalogues can help establish by comparison with new 

 catalogues minute displacements of stars on the celestial vault, 

 and can furnish the means of calculating the proper motions of 

 these stars, and consequently of determining the direction and 

 velocity of the movement of our solar system in space. 



We need not go further in the enumeration of the various lines 

 of progress and the discoveries that are due to private persons. 

 We can appreciate to a certain degree the extent of the services 

 rendered by them when we see the strongest astronomical society, 

 that of London, distributing in fifty years more than a third of its 

 annual medals to amateur astronomers. 



Other laborers than astronomers have assisted in the advance 

 of the science by furnishing amateurs easier means of examining 

 the sky and bringing the greatest exactness into their observa- 

 tions. Among them are such men as Molyneux, Dent, Grubb, 

 Alvan Clark, Secretan, and the clockmakers, machinists, and opti- 

 cians who have placed their constructive talent at the service of 

 astronomy. We should not forget to pay our tribute of admira- 

 tion to the Dudleys, Licks, and Bishoffsheims, who have disinter- 

 estedly employed their large fortunes in constructing and furnish- 

 ing observatories, and providing means to assure their existence 

 in the future. 



What emulation prevails among amateurs in astronomy! 

 They pride themselves on cultivating the science as independent 

 men, and spare neither time nor pains to secure a place in the 

 legion which enrolls Copernicus and Herschel in its ranks. One 

 can, indeed, engage with profit in those beautiful studies without 



