June i, 19 i6] 



NATURE 



289 



by Wolf, were made at Vknna on April 6, 7, 22, and 

 ^7. On the latest date Dr. Palisa observed a sort of 

 halo surrxjunding its image, and further remarked 

 that the change of daily motion was not asteroidal 

 in character. In America it has been observed at 

 Yerkes (May 4) and at the U.S. Naval Observatory 

 (May 6). It Is shown on photographs taken at Berge- 

 dorf on April 29 and May 2 ; on the earlier date its 

 magnitude was 13-2. According to observations by 

 Prof. Wolf (April 30) the nebulosity- was 15' in 

 diameter, and sharply defined towards the W.N.W., 

 the nucleus being eccentrically placed in the same 

 direction, thus presenting features justifying its classi- 

 fication with comets. The cometary character is 

 emphasised by the Babelsberg observers, who state 

 that it is immediately picked up as a comet. 

 Observations, April 6-May 6, have been used 

 by Prof. Berberich in an investigation of the orbit 

 assuming motion approximately following a great 

 circle, but no useful results had been obtained. The 

 middle-place errors for a parabola (April 6 and 22, 

 Vienna, and May 6, Babelsberg) are stated to be in- 

 admissibly large' A provisional ephemeris based on 

 hyperbolic elements (April 6, 22, and 30) represented 

 fairly closely the Babelsberg observation of May 6. 



The following orbit and ephemeris have been cal- 

 culated, also by Prof. Berberich {Asironomische Nach- 

 richten, Circular No. 508), by variation of the distance- 

 ratios from the observations of April 6, 22, and May 6 

 referred to above: — Perihelion = 19 17, June 15-916 

 G.M.T. ; w = i2o° 30' ip-3"; ^^ = 183° 15' 12-6''; t=25° 

 35' 21-9''; log q = 0227854. 



Ephemeris, Greenwich Midnight. 



R.A. Decl. 



h. m. s. o / 



June I ... 12 29 7 ... +4 28-5 



5 ... 12 28 46 ... 4 350 



9 ... 12 28 38 ... 4 39-9 



13 ... 12 28 43 ... 4 43-3 



17 ... 12 29 o ... 4 45-1 



The orbit can still be somewhat uncertain, but the 

 ephemeris should suffice verj' well for search. Peri- 

 helion passage, it should be noted, occurs in the 

 middle of June of next year, so that comet 1916b pro- 

 mises to be under observation for a very extended 

 period. At present the distance from the earth 

 is increasing. On July 3 it will be, roughly, 044 

 astronomical unit — 40 million miles — from both the 

 earth and the sun. 



A Possible New Comet. — The following message 

 from Prof. Pickering was received on May 8 at Kiel : 

 " Perrine cables bright object Thursday evening, nine 

 to ten, moved ten degrees alpha Pavonis towards 

 sun. Possibly comet" {Astronomische Nachrichten, 

 No. 4845). 



Venus. — On June 3, two days after maximum 

 brilliance, Venus will be in conjunction with the 

 moon; the planet will be 1° 19' N. Unless clouds 

 prevail this configuration will afford an excellent 

 opportunity of viewing the planet in full daylight 

 without optical help. Although the crescent phase can 

 now be distinguished with quite small hand telescopes, 

 the most interesting phenomena of the phases— the 

 more or less complete annulus seen at inferior con- 

 junction with the sun (July 3) and the secondary light, 

 •'kimiere cendree " — are only to be seen with large 

 instruments. As inferior conjunction occurs at 8h. 

 G.M.T. , English observers will be at a disadvantage. 

 Recent work indicates that a period of sun-spot maxi- 

 mum is speciallv favourable for the development of 

 luminous effects' on the dark side of the planet, but 

 there is a dearth of observations, and it is desirable 

 that a close watch should be maintained. 

 NO. 2431, VOL. 97] 



METEOROLOGICAL AND MAGNETIC 

 AUTOGRAPHS.^ 



COMPL.-MNT has been made from time to time 

 of the essential dulness of year-books of tabular 

 matter, although it is recognised that the statistics 

 must be compiled diligently year by year in order to 

 provide material for exhaustive discussion at some 

 tinie in the future. It is, theretore, all the more 

 gratifying to find in the Blue-book before us, published 

 by the authority of the Meteorological Committee, and 

 produced under the direction of Sir Napier Shaw, a 

 definite attempt made to digest the magnetic data 

 obcuined in 1913 at Eskdalemuir, somewhat on lines 

 suggested by Prof. Birkeland and also by Dr. Chree. 



Mr. L. S.' Richardson, who contributes this analysis 

 of magnetic disturbances recorded at Eskdalemuir 

 Observatory, of which he was appointed director in 

 1913, is also responsible for an appendix giving in- 

 direct comparisons by means of a standard set of 

 portable magnetic instruments, between the standard 

 instruments in use at Greenwich, Kew, Falmouth,. 

 Valencia, and Eskdalemuir in the United Kingdom, 

 and also those at De Bilt (Utrecht), Potsdam, and Val 

 Joyeux, the national magnetic observatories of Hol- 

 land, Germany, and France, thus partially anticipating 

 the comparisons made recently under the auspices of 

 the Carnegie Institution. 



Mr. Richardson gives two classes of magnetic dis- 

 turbance, whereas Prof. Birkeland indicated three, but 

 one of the three was an intermediate class, so per- 

 haps, in general, two will be sufticient, the essential 

 difference being that in one class the direction of the 

 disturbance is constant and in the other variable. 

 In connection with the well-known smoothness of the 

 vertical force traces as compared with the other 

 magnetograras, Mr. Richardson makes a suggestion 

 worthy of attention. He says: — "The fact that the 

 vertical component is perpendicular to two electrically- 

 conducting shells, the earth's surface and the upper 

 ionised air, may have an influence in reducing the 

 amplitude of its oscillations. For an oscillating cur- 

 rent forcibly maintained in either shell would induce 

 a reverse current in the other shell ; and at an observa- 

 tory which was not more than a small arc of the 

 earth's surface away from the currents, the reverse 

 current, while partly neutralising the vertical force, 

 would increase the horizontal component. For slower 

 oscillations the induced current would be diminished 

 bv the electric resistance. The system is like a 

 transformer with a short-circuited secondary coil. The 

 vertical force is the main flux of the transformer. 

 The horizontal components represent the magnetic 

 leakage." 



The magnetic data from Eskdalemuir form the prin- 

 cipal part of the magnetic portion of the Year Book, the 

 Kew data being given in much less detail, Valencia 

 being unprovided with magnetographs, and Falmouth 

 practically discontinued. Meteorology is represented 

 bv five stations, Aberdeen being the additional con- 

 tributor, monthly means for each hour of the day 

 being tabulated for temperature, pressure, and rela- 

 tive humidity of the air, for wind velocit}-, and rain- 

 fall, sunshine tables being added. 



It is curious to note that the mean warmest hour at 

 Falmouth is invariably i p.m., while at the other 

 observatories it is generally 2 p.m. or 3 p.m. The 

 arrangement of the tables is that, except for Eskdale- 

 muir. the establishment of which is too recent for 

 normals to have any significance, what is ptinted is a 



1 Meteorol<H^cal Office. British Meteorological and Magnetic Year 

 Book, 1913. F^rt iv., section a. Hourly Values from Autographic Records^ 

 Pp- 97- (Edinburgh: H.M.S.O. ; London: Meteorok^ical Office, 1915. 

 Price 5^ 



