ASTRONOMY, PROGRESS OP, IN 1894. 



53 



panying noise or appearance of an explosion 

 during visibility. It was seen at various places 

 in the colony, and all agree that no noise was 

 heard or explosion seen." 



A majority of fire balls move in the same di- 

 rection as the earth, or from west to east, and, 

 as the motion of both is about the sun, such me- 

 teors overtake the earth. On the contrary, those 

 having a retrograde motion are themselves over- 

 taken by the earth. Results derived from ob- 

 servation of 321 of the largest fire balls seen 

 Curing the past thirty years show 59'2 per cent, 

 of the former class and 40'8 per cent, of the 

 latter. 



Binary Systems. The following are a few 

 binary systems for which orbits of more or less 

 exactness have been computed : 



NAME OF STAR. 



Period 

 in years. 



Delta Equulei 11 "5 



Kappa Pegasi 15'5 



Zeta Sagittarii 18 



85 Pegasi 22 



Beta Delphini 24 



Zeta Herculis 34 



Eta Corona Borealis 42 



Sirius ... . . 52 



NAME OF STAU. 



ChiUrsaj 



Alpha Centauri 



70 Ophiuchi 



Gamma Virginia 



Delta Cygni 



61 Cygni 



Castor 



Period 

 in years' 



61 



81 

 88 

 185 

 377 

 782 

 1,001 



Zeta Aquarii 1,624 



Constant of Aberration. Mr. Preston, of the 

 United States Coast Survey, having discussed the 

 observations made at Waikiki, Hawaiian Islands, 

 finds it necessary to make a correction to the 

 generally accepted value of the constant of 

 aberration from 20-445" to 20-433" 0'034. This 

 value, combined with the latest determinations 

 of the velocity of light (186,333 miles) and 

 Clark's value of the earth's radius (3,963-3 miles), 

 gives the sun's distance and equatorial horizontal 

 parallax as follow : Distance, 92,700,000 miles ; 

 parallax, 8'82". 



Change In the Astronomical Day. In 

 answer to the question asked of astronomers in 

 all countries by the Physical Society of Toronto, 

 whether it be desirable that the astronomical 

 day should begin at midnight instead of at noon, 

 179 replies were received 107 in favor of and 

 63 adverse to the proposed change. Of the op- 

 position most were Germans. The time indi- 

 cated for the inauguration of this change of the 

 day's beginning is the first day of the twentieth 

 century, Jan. i, 1901. 



Universal-time Movement. Considerable 

 progress has been made, both during the past 

 and the present year, by the project for the 

 adoption by the Eastern Continent of a zonal 

 system of time similar to that which for several 

 years has been in use in the United States and 

 Canada. Germany has adopted mid-European 

 time, one hour fast of Greenwich, and made it 

 the legal time of the German Empire. The 

 same system obtains in Italy, Denmark, and 

 Switzerland. England, Belgium, and Holland 

 use Greenwich time. Japan and Australia are 

 nine hours fast of Greenwich time. The 

 United States and Canada are four, five, six, 

 seven, and eight hours slow of Greenwich time, 

 and the differences are named colonial, eastern, 

 central, mountain, and Pacific time, respective- 

 ly. When the standard time was changed in 

 Italy the twenty-four hour system of reckoning 

 was introduced also, hour being midnight. 



Astrographic Charts. Work on these charts 

 may now be regarded as fairly begun. Up to 



the beginning of the present year reports were 

 received from 7 of the associated observatories 

 that the plates secured amounted to 1,731, the 

 total number assigned to them being 8,308. If 

 the unreported observatories are equally ad- 

 vanced there should be no difficulty in complet- 

 ing the catalogue plates before the year 1900. 

 Of chart plates, however, only 415 have been 

 taken by the same 7 observatories, so that the 

 date of completion of the long-exposure nega- 

 tives, even without duplication, is still very un- 

 certain. Letters from the directors of several 

 observatories engaged in the work testify to the 

 practical difficulties encountered by them, notably 

 with the Rescaux, the films of which seem liable 

 to perish, causing faults in the photographs. 



Celestial Photography. The application of 

 photography to astronomical purposes is rapidly 

 extending, and is arousing a spirit of emulation 

 not confined to the great observatories, nor to 

 eminent specialists like Roberts and Barnard, 

 and is achieving valuable results. 



MM. Loewy and Puiseux, of the Paris Ob- 

 servatory, at a recent meeting of the Paris Acad- 

 emy of Sciences, exhibited some photographs of 

 the moon, taken with the equatorial coudee, which 

 were larger than those taken at Lick Observa- 

 tory, and bore enlarging well. One of the en- 

 largements represented the moon on a scale 

 nearly six feet in diameter, rare, indeed, because 

 the atmosphere will seldom allow the taking of 

 a photograph of which such enlargement is pos- 



Photographic Nebula?. Suspecting that 

 there was a nebulous region hitherto unknown 

 in the vicinity of the Pleiades, not reckoning the 

 nebulae of the cluster itself, Dr. Barnard subject- 

 ed that portion of the sky to an exposure of 

 IQh i5m ? an( j secure( ] a number of singular curved 

 and streaky nebulosities apparently connected 

 with the Pleiades, and extending all about the 

 group. Some of these streams stretch out ir- 

 regularly several degrees on either side of the 

 cluster. 



North of the Pleiades, from right ascension 

 3 h 20 m to over 4 h , and from declination + 30 to 

 several degrees farther north, is a district singu- 

 larly devoid of small stars, but filled with large 

 masses of exceedingly diffused nebulosity, never 

 before known or imagined. Differing from all 

 other nebulous clusters, the nebulosity of the 

 Pleiades is condensed about the individual stars. 



In December, 1892, and January, 1893, the 

 entire constellation of Cassiopeia was photo- 

 graphed by Dr. Max Wolf, which revealed the 

 structure of the Milky Way. Also numerous 

 nebula? were recorded on the plates (with expo- 

 sures of fifteen and sixteen hours), which were to 

 a large extent connected one with another by 

 faint nebulous bands and streamers. He men- 

 tions as a typical form of these nebulae that of 

 a funnel narrowing to a curved tube or pipe, 

 which ends in a chain or series of stars. 



Publications. Prof. S. W. Burnham, in a 

 quarto volume of 255 pages, Vol. II, "Annals of 

 Lick Observatory," has recorded his own work 

 on double stars the result of his studies with 

 the 36-inch and 12-inch refractors of that insti- 

 tution. He gives full details of microraetrical 

 measurements of between 800 and 900 objects. 

 In discussing his measures of the celebrated 



