112 



NA TURE 



[June i, 1893 



and the observations were made from the Observatory erected by 

 the Expedition of the Bureau des Longitudes. With an eye- 

 piece magnifying 190 times he observed several occultations of 

 solar spots by the moon, and in about fifteen cases he noticed 

 the phenomenon that is equivalent to that seen in observations of 

 the Transit of Venus and linown as the black drop. It was pro- 

 duced, he says, not only at the contact of large spots, but at the 

 point of contact of small ones, and even of the simple filaments 

 forming the penumbrse of spots. M. Bigourdan also made a 

 special look for the phenomena known as Baily's beads, some- 

 limes seen when the sun has been reduced to a very fine crescent 

 by the advance of the lunar disc, but from all accounts he seems 

 to have been unable to see any trace of them. A search round 

 the sun for an intra-Mercurial planet, with a telescope giving a 

 field of 25', was aho made, but with no satisfactory result, since 

 he says that his instrument was not suited for that purpose : the 

 negative result thus obtained affords no argument against the 

 existence of such a body. The duration of totality lasted 

 exactly 4m. Is. 



Finlay's Comet(i886, VII.). — The following is the current 

 ephemeris of this periodic comet, as given in Astronomische 

 Nachrichten, No. 3164: — 



12/2. M.T. Paris. 



Aurora Observations.— -In the event of Lieut. Peary's 

 expedition to a high station in North Greenland (about Lat. 

 77' 30' N. and Long. 70° 15' W.), where regular observations 

 of the aurora will be undertaken, it is hoped that everyone, 

 wherever he may be, will help to supplement these observations 

 by noting himself the times of absence and presence of this 

 phenomenon. With so many workers in so many lands, it is 

 needless to say that a systematic method of recording what is 

 seen should be followed. With the intention of supplying this 

 demand, Mr. M. A. Veeder has issued a set of blanks similar 

 to those that will be used in the expedition, so that when 

 properly filled up comparisons can be made in detail. In 

 addition to the investigation of the local distribution of the 

 aurora, it is hoped that the electro-magnetic conditions of solar 

 origin may be more inquired into, and it is on this account that 

 these circulars have been .«ent to both solar and magnetical 

 observatories as well as to individual observers. As for the 

 Arctic records, they will be continuous whenever observation is 

 possible, relays of observers connected with the expedition 

 relieving each other. In making such observations it is empha- 

 sised here that minute descriptions of the formation of arches, 

 streamers, prismatic colours, and the like, accompanying such 

 variations in the extent of displays, are of interest, but are far 

 less important than that the times should be noted as accurately 

 as possible. Any one desiring these blanks can be supplied 

 directly by applying to M. A. Veeder, New York. 



The Constant of Aberration. — Prof Chandler, in the 

 Astronomical journal {tio. 296;, gives the third of his most 

 important papers relating to the constant of aberration, treating 

 in this article specially of Struve's Prime- Vertical Observa- 

 tion=, 1840-55, from the new point of view with respect to the 

 variation of latitude. In this discussion, in addition to a direct 

 solution for all the unknowns, he has made an indeterminate 

 one, employing the constants pertaining to the 427-day term, 

 and expressing the unknowns in terms of y and s. As regards 

 the former solution, employing the observations of the seven 

 stars from the years 1840-42, the value of the observations ob- 

 tained is 2o"'533, Struve's value from the same material being 

 20" -445, and for the whole data from 1840-55 the aberration is 

 20"-5i4. This last-mentioned value would be the "definite 

 value from Struve's Prime- Vertical Observations, if we accept the 

 direct solution as the best," but he savs the inditenninale solu- 

 tion throws doubt upon this point. The definite value, as given 

 by this solution, gives 2o"-48l -t- O'lii/ + O'Zloz; and, since 

 as yet the most probable values of these constants are not known, 



NO. 123 r, VOL. 48] 



those of the 427-day period applied to the special case of 

 Polaris, which were independent of the aberration, give, on 

 this assumption, 20" '474, a value, as will be noticed, smaller 

 than that by the direct solution. The value 2o"'50O for the 

 aberration constant is, according to Prof Chandler, too great, 

 as inferred from the discussion here given. As a " matter ot 

 interest " he gives the values of the aberrations deduced from 

 the observations of the several stars made in 1840-42. 



The Astronomical Day. — "Is it desirable, all interests 

 considered, that on and after January I, 1901, the astronomical 

 day should everywhere begin at mean midnight?" This is 

 the question that has been put forward by a joint committee 

 of the Canadian Institute and the Astronomical and Physical 

 Society of Toronto, and printed in a circular-letter addressed to 

 astronomers of all nations. Many of our readers may remem- 

 ber that as far back as 1884 the Washington International 

 Conference carried unanimously the following resolution, there 

 being representatives of twenty-five nations, " counting among 

 them several astronomers of world-wide fame," that "the confer- 

 ence expresses the hope that as soon as may be practicable, the 

 astronomical and nautical days will be arranged everywhere to 

 begin at mean midnight." That the astronomical and civil day 

 should start together at the same moment seems without doubt 

 the right method of procedure, for what is gained really by 

 reckoning the astronomical time from noon and the civil from 

 the preceding midnight ? It is true that changes will have to be 

 made in the Nautical Almanac, and all such-like year-books, 

 both astronomical and nautical ; but on the assumption that the 

 change is made simultaneously by all nations, and taking into 

 account that such a change cannot come into vogue for five or 

 six years on account of the fact that these books are printed a 

 few years in advance, there seems really no difiiculty ahead. 

 The suggestion that the change, if made, should take place with 

 the change of the century seems to be an excellent epoch for 

 such a transition, for besides giving time for a thorough dis- 

 cussion of so important a question, it will, as Otto Struve says, 

 " stamp it.self on the memory of all who hereafter would be 

 busied in the investigations in which exact chronology plays a 

 part." 



Royal Observatory, Greenwich. — The Annual Visita- 

 tion of the Royal Observatory at Greenwich by the Board of 

 Visitors takes place on Saturday, June 3 next. The Observa'ory 

 will be open for inspection at 3 p.m. 



GEOGRAPHICAL NOTES. 



Dr. Nansen writes confirming the statement made in this 

 column as to the baselessness of the assertions regarding the 

 failure of his expedition. He is making rapid progress with his 

 preparations, and expects to sail in the I'ram on his great venture 

 on June 20. 



The most recent change of name in Africa is the adop'.ion 

 of the official title Niger Coast Protectorate for what was 

 previously known as the Oil Rivers Protectorate, comprising the 

 coastward part of the Niger delta. 



Natal, which has been a British colony for fifty years, has 

 entered upon the final stage of colonial independence by the 

 adoption of responsible government. It is expected that this 

 step will lead to a rapid development of the resources of the 

 country, and a considerable extension of its railways. 



The Antarctic whaler Balana put into Portland Roads for 

 coal on May 25, and reached Dundee on May 30, being the first 

 to return. Mr. W. S. Bruce, who was on board as surgeon and in 

 charge of scientific observations, reports that the homeward trip 

 was favoured by very fine weather. He confirms our fear that 

 opportunities for scientific work had often to be lost on account 

 of the purely commercial character of the trip, and the rigid in- 

 terpretation of his instructions by the capt.ain. An account of 

 the voyage and its results will probably be given to the meeting 

 of the British Association at Nottingham. On the return 

 journey a series of floats was thrown overboard from the Ant- 

 arctic ice-margin to the equator, in order to endeavour to get 

 light on the direction and speed of the currents. The lowest 

 air temperature experienced amongst the ice was 21° F. 



The new number of the Geographical Journal publishes an 

 old minute of a committee of the Royal Geographical Society 

 held in 1845 to consider the nomenclature °^ ^^ oceans. At 



