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THE GUIDE TO NATURE 



probably better than any other the ex- 

 traordinary accuracy of modern astro- 

 nomical observations. 



There are several different methods 

 employed for measuring these exces- 

 sively minute displacements. The most 

 direct one is to actually measure with 

 the so-called Meridian Circle the suc- 

 cessive positions of the star on the sky 

 — that is, its distance above or below 

 the Celestial Equator and its angular 

 distance from the Vernal Equinox. If 

 it is found that the point of the sphere 

 occupied by the star does not remain 

 constant but that it apparently moves 

 along a little elliptic curve, we know 

 that this apparent motion is wholly 

 due to the nearness of the star. The 

 nearer the star is to us the greater 

 will be its displacement; the computa- 

 tion of its absolute distance from the 

 amount of its displacement is a very 

 simple matter. 



Another method now very exten- 

 sively employed is to measure the posi- 

 tion of the nearer star with reference 

 to one or more stars which are so in- 

 finitely far away that these so-called 

 comparison stars will not seem to move 

 at all as we move around the sun. This 

 can either be done by direct measures 

 at the telescope or, as is now more 

 usual, by photography. If at several 

 different dates a very small region of 

 the heavens about the star whose dis- 

 tance is to be measured is photographed 

 and if the plates are then carefully 

 measured under a microscope, a dis- 

 placement of any one star can thus be 

 found with reference to the others. 



It is in this way that the distances 

 of the nearer stars are measured, and 

 the results are so enormous that thev 

 overwhelm the imagination. We find 

 that there is no star so near that the 

 light with which we view it, though 

 traveling with the inconceivable velo- 

 city of nearly 200,000 miles a second, 

 has occupied less than several years in 

 coming to us. while manv even of the 

 brighter stars are no less than 100 light 

 years awav. 



And it is still more remarkable that 

 many of the very bright stars of the sky 

 are so remote that thev undergfo no dis- 

 placement arising from our motion 

 about the sun at all. It mav be that 

 their light has occupied thousands of 

 years in coming to us. and it is certain 

 that they are as far as 100 light years 



away. The brilliant Arcturus now so» 

 conspicuous in the western sky is one 

 of these. This star is certainly many 

 thousands of times brighter than our 

 sun, for though it seems so bright to 

 us it is so infinitely remote that its- 

 distance cannot be measured. 



Truly the great cloud of suns which 

 surrounds us is of so enormous a mag- 

 nitude that our whole solar system 

 seems to shrink into nothing in com- 

 parison with it. 



The Ennobling Effect of Astronomy. 



Dr. Brashear recently spoke at the- 

 annual banquet of the Providence 

 Society of Mechanical Engineers. From 

 an account of his address published in 

 "Popular Astronomy" we quote the 

 following : 



"In closing, Dr. Brashear spoke of 

 the lofty and ennobling influence which 

 the study of 'the supreme science' has 

 upon the human mind and soul, and 

 spoke of a well-known millionaire, 

 whose son was not all that his father 

 desired him to be. The father had gone 

 to Dr. Brashear and asked him to take 

 the son into the Observatory, and show 

 him some of the marvels to be seen 

 through the telescope. This the Doctor 

 had done, the young man had become 

 interested in the study, and the inevi- 

 table ennobling effect had followed. 

 The young man is now one of the most 

 highly respected men in the city where 

 he lives." 



C. C. Georgeson, of the United States 

 Department of Agriculture, has been 

 doing some special work on the native 

 wild fruits of Alaska with the hope of 

 breeding new cold-resistant varieties of 

 the cultivated species. Already he has 

 produced nearly four thousand hybrids 

 between the cultivated strawberry and 

 wild sort that grows along the Alaskan 

 coast. Other crosses between exotic 

 and native raspberries, gooseberries, 

 and currants have thus far been less 

 successful. There is also a wild Alas- 

 kan crab apple which it has been hoped 

 to cross with some of the hardiest of 

 our northern cultivated sorts, since 

 even the most resistant of these latter 

 are grown only with the greatest dififi- 

 cultv so close to the Arctic Circle. 



