268 



SCIENCE. 



[N. S. Vol. V. No. 111. 



ing the last session of Congress. The estimates 

 for the next fiscal year contain, however, a 

 recommendation for an appropriation of $6,000 

 per annum for this office, in the expectation that 

 it will be created by Congress. 



yotjng's 'keveesing layer.' 

 In a careful review of the progress of astron- 

 omy during the year 1896, published in the 

 London Times of January 14th, the author 

 writes: "At Novaya Zemlya, Mr. Shackelton, 

 using a spectroscope without a slit — since the 

 extremely narrow sickle of light at the moon's 

 limb made a slit unnecessary — and timing the 

 exposure of his plate to the precise moment of 

 the progressing eclipse which corresponded to 

 that at which Professor Young made his classi- 

 cal observation by eye in 1870, was fortunate 

 enough, with an exposure of half a second, to 

 secure a permanent record of Young's revers- 

 ing layer. It consists of a very narrow spec- 

 trum of bright lines, which are, indeed, the 

 Fraunhofer lines reversed. A plate exposed 

 two seconds later showed a comparatively sim- 

 ple chromosphere spectrum. The congratula- 

 tions of astronomers are due to Professor 

 Young upon this complete, though late, con- 

 firmation of his observation of 1870 and of his 

 views, speaking broadly, of solar absorption 

 founded upon it. Professor Young, after a 

 careful comparison of the Novaya Zemlya 

 photograph with a Fraunhofer spectrum taken 

 with the same prisms, but with a collimator 

 and slit before the prisms, writes : 



" ' With very few exceptions every Fraunhofer line 

 finds its correlative in the 'flash spectrum.' I do 

 not see but that the evidence as to the origin of the 

 great majority of the Fraunhofer lines within a very 

 short distance from the photosphere is practically 

 complete. Very possibly some of the absorption 

 occurs at higher levels ; but it seems to me clear that 

 most of the absorbing metallic vapours are at the 

 base of the chromosphere, in a thin stratum or layer, 

 if one chooses to call it so ; not that I suppose it to 

 be a quiescent sheet or a stratum in any different 

 sense from the chromosphere itself.' 



' ' Professor Young further points out that it 

 would be absurd to compare the number of 

 bright lines of this ' flash ' spectrum, taken 

 with two prisms only, a lens of 10-iu. focus and 

 no slit, with the number of dark lines in Row- 



land's great solar map, photographed with a 

 large concave grating, a fine slit, and every 

 possible refinement of adjustment." 



MOTOR CAREIAGE8. 



In view of the scientific and practical im- 

 portance of motor carriages, we give the report 

 made by the jurors in connection with the re- 

 cent exhibition at the Crystal Palace, London : 



' ' Although none of the vehicles exhibited ap- 

 proached that degree of perfection which would 

 place them beyond the adverse criticism which 

 condemns any evidence of an unrealized at- 

 tempt, they are of opinion that several of the 

 vehicles shown and worked in the Crystal 

 Palace grounds have reached a degree of prac- 

 tical sufficiency meriting some distinctive mark 

 of appreciation. Most of the vehicles, which 

 have withstood the test of considerably hard 

 daily work, were propelled by motors actuated 

 by the internal combustion of light oils, such 

 as benzoline. The use of these light oils in this 

 country has been discouraged, although the 

 cause of this is probably due more to fiscal and 

 to other restrictive regulations than to any real 

 evidence of danger attaching to it. Most of the 

 carriages exhibited and worked in the grounds 

 have motors supplied with hydrocarbon vapor, 

 produced by the passage of air through some 

 form of carburetter containing benzoline. This 

 vapor, mixed with air, and compressed and 

 heated by the incoming stroke of the motor 

 piston, was, with one exception, ignited by an 

 electric spark, obtained by means of a secondary 

 battery and induction coil. The one exception 

 was the carriage of Peugeot, fitted with a Daim- 

 ler motor, and lent by Sir David Salomons. 

 This vehicle, however, did not come within our 

 cognizance at the time of our visit with respect 

 to the merits and awards. 



' ' We have carefully considered the various 

 points in the construction, detail and working 

 of the several vehicles and their motors, and 

 we are very strongly of opinion that these ben- 

 zoline motor carriages do, even in their present 

 state of advance towards sufficiency, show that 

 such motors may be practically employed for 

 propelling vehicles of various kinds and for vari- 

 ous purposes. The carriage of M. Delahaye 

 showed a distinct step in advance upon the 



