444 



SCIENCE, 



[Vol. VI., No. 146. 



This, as shown by studying the spectrum of frigid 

 masses, is colder than the temperature of melting 

 ice. 



By comparing the mean of the spectra obtained 

 in summer with that of those obtained in winter, 

 it is evident that a much greater amount of heat 

 is received from the moon in winter than in sum- 

 mer. This may simply be due to the greater 

 amount of aqueous vapor in our own atmosphere 

 in the summer, as contrasted with the winter 

 clarity. By directing the bolometer to the zenith 

 and to the horizon, the temperature of space has 

 also been measured by direct experiment for the 

 first time, and the amazing transparency of our 

 atmosphere to radiation of the earth's heat re- 

 vealed ; for his experiments show that our atmos- 

 phere transmits the earth's heat more readily than 

 the sun's. 



Professor Newcomb discussed the subject, 

 ' When shall the astronomical day begin ? ' He took 

 the ground that the inconvenience arising from 

 the discordance between the civil and astronomical 

 measure of time had been greatly exaggerated. It 

 depended, not upon the number of people who had 

 to use the one time, nor upon the number who had 

 to use the other, but upon the number of times one 

 had to be changed into the other. As an illustra- 

 tion, he said that the inhabitants of the planet 

 Mars might use one reckoning of time, and we 

 another, without the slightest inconvenience to 

 the inhabitants of either planet. On the other 

 hand, the proposed change of the beginning of the 

 astronomical day from noon to midnight would 

 be productive of confusion both to ourselves and 

 our successors, the end of which it would be hard 

 to see. It was, in fact, nothing less than a change 

 in language : it was proposed that * three hours 

 mean time ' should hereafter mean what ' fifteen 

 hours ' had liitherto meant, and vice versa. He 

 explained, however, that his objections applied 

 only to that resolution of the International con- 

 ference which proposed to change the begimiing 

 of the local astronomical day to midnight, and 

 that he made no objection to the introduction into 

 astronomy of the universal day, beginning at 

 Greenwich midnight, provided that this reckon- 

 ing of time was expressed in language which 

 would clearly distinguish it from any other. 



Professor C. H. F. Peters sustained the view of 

 Professor Newcomb, while Professors Young and 

 Graham Bell opposed it. Professor Young held 

 that the introduction of civil time into astronomi- 

 cal reckoning would be a great convenience in 

 designating without ambiguity the times of obser- 

 vations, especially those made in the forenoon ; 

 he cited cases in which correspondents had written 

 to him to inquire on which day such observations 



had been made. He considered that the public at 

 large were ready to adopt the recommendations of 

 the International conference, and that astronomers 

 should not be behind them in doing so. 



Professor Bell held that there were three strong 

 reasons for the adoption of the change. The first 

 was that the Meridian conference which proposed 

 it was called by our government, and that we were 

 bound to follow its recommendations. Another 

 reason was that the astronomer royal at Green- 

 wich had adopted the new reckoning at the begin- 

 ning of the present year, so that the reform was 

 secure if Americans would only follow his ex- 

 ample. Third, he considered that ambiguity 

 would be avoided in the records of astronomical or 

 other events. For example, beginning the day at 

 noon, it might happen that an eclipse of the sun 

 occurred before noon at one place, and after 

 noon at a place farther east. Then the historian of 

 the future might be perplexed by finding the eclipse 

 recorded in one place as beginning on one day, 

 and in another place as beginning on the day after. 



In reply to Professor Bell, Professor Newcomb 

 called attention to the case when an eclipse of the 

 moon would be observed before midnight at one 

 place, and after midnight at another. So that if 

 the day began at midnight the same trouble would 

 arise that Professor Bell had pointed out in regard 

 to the solar eclipse. 



In reply to Professor Young, he said that in 

 order to bring the astronomical and civil reckon- 

 ing of time into accord it was necessary either that 

 astronomers should subdivide the day into a.m. 

 and P.M., or that the general public should count 

 the hours up to twenty-four. He considered 

 neither course feasible. 



Other astronomical papers were read by Mr. 

 O. T. Sherman, who exhibited spectra of /? Lyi'ae 

 and }' Casseiopeiae, showing the existence of bright 

 lines which coincide closely with those of the solar 

 cln-omosphere ; by Prof. C. H. F. Peters, who be- 

 lieves that he has been able to make a plausible hy- 

 pothesis for each of the twenty-two stars observed 

 by Flamsteed, which were afterwards supposed to be 

 lost ; and by Prof. C. A. Young, on the fading star 

 in the nebula of Andromeda, which he had found 

 also to be of variable color. 



On the biological side, the chie^" interest centred 

 in the exposition, by Dr. A. Grahan: BeU, of the 

 first results of the investigations it had been known 

 he was making in hereditary deafness. A report 

 of this paper will appear in Science of Nov. 27. 



Space prevents our entering into detail concern- 

 ing other paj)ers which had mostly only a technical 

 interest. A complete list will be found in our 

 notes. The next meeting will be the annual session 

 at Washington, in May, 1886. 



