POPULAR MISCELLANY 



573 



were well shown. The investigation having 

 been resumed in 1885, with a larger tele- 

 scope, one hundred and seventeen stars 

 within 1 degree of the pole, each of them 

 no brighter than the fourteenth magnitude, 

 left trails. The average deviation of the 

 measures of the brightness of these stars on 

 different photographs was less than a tenth 

 of a magnitude, a greater accordance than 

 is given by any other photographic method. 

 A similar result was obtained from the 

 Pleiades, of which group more than fifty 

 stars left trails. Trails are now being pho- 

 tographed of all the stars north of 30 

 in all right ascensions, and the work has 

 been completed for more than half of the 

 sky. By photographing on the same plate 

 polar stars near their upper and lower cul- 

 minations, material has been accumulated 

 for determining the atmospheric absorption 

 on each night of observation. A study has 

 been made of the application of photogra- 

 phy to the transit-instrument. By placing 

 a large prism in front of the object-glass, 

 excellent stellar spectra have been obtained. 

 An exposure of five minutes gives the spec- 

 tra of all stars brighter than the sixth mag- 

 nitude within a region 10 square. About 

 half of the region north of 25 has been 

 photographed in this way. With an ex- 

 posure of an hour, the spectra of stars no 

 brighter than the ninth magnitude are 

 shown. Over a hundred stars have thus 

 been taken simultaneously on a plate by a 

 single exposure. Miscellaneous observations 

 have been secured of the Pleiades, of the 

 nebula in Orion, of Jupiter's satellites, and 

 of various other objects ; also of the new 

 star in Orion, and of its spectrum, and one 

 plate showing that this star must have been 

 much fainter on November 9, 1S85, than 

 when discovered five weeks later. 



The Prospect for Silk-Culture in the 

 United States. Dr. C. V. Riley, of the En- 

 tomological Division of the Agricultural Bu- 

 reau, said in the preface to the second edi- 

 tion of his " Manual of Silk-Culture," in 

 1882, that the elements of successful silk- 

 culture on a large scale were entirely want- 

 ing in thi3 country ; that " the profits of 

 silk-culture are always so small that exten- 

 sive operations by organized bodies must 

 prove unprofitable where capital finds so 



many more lucrative fields for employment', 

 that extensive silk-raising is fraught with 

 dangers that do not beset less ambitious 

 operations, " and that silk-culture is to be 

 recommended only as a light and pleasant 

 employment for those members of the farm- 

 er's household who either can not do or 

 are not engaged in otherwise remunerative 

 work." In the latest edition of the " Man- 

 ual " (1886) the author regrets that his origi- 

 nal estimates, made in 1879, of the profita- 

 bleness of the enterprise have been criti- 

 cised because they had not been realized 

 the trade had, in fact, been passing through 

 a period of depression ; and he reiterates 

 the caution that " silk-raising on an exten- 

 sive scale is fraught with so many dangers, 

 that it is inadvisable to invest capital in 

 such an enterprise." Silk-culture, he says 

 in another place, " is not (and it never has 

 been) an exceedingly profitable business ; 

 but it adds vast wealth to the nations en- 

 gaged in it, for the simple reason that it can 

 be pursued by the humblest and poorest, 

 and requires so little outlay. The question 

 of its establishment in the United States is, 

 as I have elsewhere said, a question of add- 

 ing to our own productive resources. There 

 are hundreds of thousands of families in the 

 United States to-day who would be most 

 willing to add a few dollars to their annual 

 income, by giving light and easy employ- 

 ment for a few months each year to the 

 more aged, to the young, and especially to 

 the women of the family, who may have no 

 other means of profitably employing their 

 time." 



Wood and Metal for Railroad-Ties. 



M. Henri Mathieu, chief-engineer of the 

 French railway du Midi, from observations 

 on the consumption of the wood tics on 

 French railways, has found that their dura- 

 tion depends upon several factors, among 

 which are the material employed, the cli- 

 mate, the ground, and the ballasting. It 

 principally depends upon the system of pre- 

 paring the ties, and the quality of the anti- 

 septic material ; and the observations made 

 on one line often differ from those made on 

 another line. Averaging the results oak 

 ties, not prepared, last fourteen years ; when 

 creosoted, eighteen years. Creosoted beech 

 ties last from eight to ten years ; creosoted 



