4IO 



NA TURE 



[February 3, 1910 



tion, the perihelion distance given in the elements, viz. 

 nearly 4,000,000 miles, is probably much too small. Prof. 

 Kobold has calculated the following elements and ephemeris 

 from observations made on January 18, 20, and 23 ; — 



Elements. 

 T =1910, Januiry 17C7 G.M.T. 



=311' i< 



The spectrum of the comet has been observed a number 

 of times at Cambridge, and found to consist of a bright 

 yellow line in a continuous spectrum, thus far confirming 

 the Lick observation. To the Times Sir Robert Ball re- 

 ported this line as being due to sodium or helium, and 

 stated, on January 26, that it was growing fainter. In a 



of ihe New Comet on January 29 {.W. E. RoLston,'. 



subsequent interview Mr. Hinks is reported to have said 

 that Prof. Ne wall's observations showed that the spectrum 

 of the comet's tail was purely monochromatic, the one line 

 being due to sodium or helium, probably the latter. It 

 will be reniembered that Copeland and Lohse observed 

 bright yellow lines in the spectrum of the great comet of 

 1882, but they were confirmed by T+iollon and Gouy in 

 ascribing them to the sodium, D, lines; further, they 

 found them displaced towards the red sufficiently to give 

 a measure of the comet's velocity of recession which 

 agreed fairly well with the velocity determined geometric- 

 ally. Should the presence of helium in the spectra of 

 comets which have small perihelion distances be estab- 

 lished, it might throw more light on Prof. Newall's sugges- 

 tion that possibly the' cyanogen spectrum so frequently 

 observed is produced in the medium through which the 

 comet is travelling ; but the observation of cometary spectra 

 is a delicate one, and not until the details of the observa- 

 tions have been thoroughly discussed by those who made 

 them may any semblance of a definite conclusion be 

 arrived at. 



Prof. Dreyer reports (the Times, January 27) that 

 observations made with the lo-inch refractor at .Armagh 

 on January 21 and 24 showed a fan-shaped jet on the side 

 of the comet's head turned towards the sun. The matter 

 issuing from the fan, and turning back on both sides to 

 form the tail, was distinctly broader south-cast of the 

 nucleus than west of it. 



Observations at the London observatories have been 

 greatly interfered with by the smoke and haze at the 

 horizon and by clouds. On January 25 the comet was 

 " glimpsed " at Greenwich, and its position was determined 

 the following day. 



Successful photographs were obtained on January 28 and 

 30, and show, in addition to the two main streamers, a 

 much fainter tail which makes a considerable angle with 

 the main tail and gives the comet an appearance similar 

 to that of the great southern comet of igoi. 



At the Solar Physics Observatory, South Kensington, 

 Dr. Lockyer saw the comet on Friday evening, January 28, 

 just before 6 p.m., but there was not time to determine its 

 position exactly before clouds again interfered. 



\"isual observations made at South Harrow on January 29 

 by Mr. Rolston showed the comet as a magnificent object 

 with a curved tail extending nearly to | Pegasi, that is to 

 say, about 20°. The rough sketch reproduced herewith 

 shows the relative position and extension at 6.20 p.m. 



Mr. F. C. Constable, of Wick Court, near Bristol, 

 directs attention to a projection extending from the base 

 of tlie double tail on the side nearer to Venus. In a 

 rough sketch, made at 6.20 p.m. on January 30, he shows 

 this projection as a short, bushy tail inclined some 20° to 

 the axis of the main tail. 



Father Cortie states (Times, January 29) that on 

 January 26 the comet was seen at Stonyhurst from 5.40 

 to 7 p.m. ; the nucleus was as bright as a first-magnitude 

 star, and the tail could be traced to a distance of 10°. 

 Observed with the 15-inch refractor, the region near the 

 head showed a deep, wide, dark segment running down 

 the tail, recalling to mind the drawings of Donati's comet 

 made by Bond and Pape. 



Two photographs taken with the 6-inch Dallmeyer 

 portrait lens show a cloud of particles to the east of the 

 main tail, bounded by a ray making an angle of about 

 30° with the main axis ; presumably this is the projection 

 also observed by Mr. Constable. 



On the Stonyhurst photographs the tail can be traced 

 to a distance of 4°, and has the appearance of being a 

 hollow cone, the two bright wings of the tail being the 

 sides of the cone in projection. A glimpse at the speC' 

 trum with a small McClean direct-vision spectroscope 

 showed that it was continuous, with a decided brightening 

 in the green, presumably due to a hydrocarbon band ; the 

 colour of the comet was decidedly yellowish. 



,\ number of observations are recorded in No. 4385 of 

 the Astronomische Naclirichten. M. Gonnessiat, Algiers, 

 suggests that between January 19 and 20 the brightness 

 decreased two magnitudes, and other observers record the 

 rapid decrease. On January 23 Prof. Kobold found the 

 nucleus to be of the third magnitude and the length of 

 the tail to be 15°. From the Times (January 31) we learn 

 that, presumably on January 28 or 29, Prof. Nijland, 

 Utrecht, saw a tail 30° long, strongly convex towards the 

 west, and reaching a few degrees to the left from 

 a Pegasi. On Saturday Prof. Turner recorded a faint 

 tail 15° or 20° long. Mdlle. de Robeck, of Inistioge, 

 Kilkenny, reports that the comet was well seen at that 

 place on the four nights succeeding January 22, and pro- 

 vided a fine spectacle just after sunset ; she likens it to an 

 egret's plume, which stood out with remarkable clearness 

 against the golden-red background of the sunset sky. 



A Times correspondent, writing from Malvern, directs 

 attention to a remarkable glare which he saw, on 

 January 30, extending from the concave, or southern, side 

 of the tail well up into the square of Pegasus. This 

 lateral extension through an angle of nearly 80° set with 

 the stars. 



THE MES.SINA EARTHOV.AKE AND THE 

 A C COM PA N YING ~SE.i- WA VES . 

 A SU.MM.\RY of Dr. M. Baratta's prehminary report 

 -^ on the Messina earthquake has been given recently 

 in N.^TURE (December 16, 1909, p. 203). Since then two 

 other memoirs have appeared, one a preliminary report by 

 Prof. Omori (Bulletin of the Imperial Earthquake Investi- 

 gation Committee, vol. iii.. No. 2, Tokyo), and the other 

 a detailed account by Prof. G. Platania of the accompany- 

 ing sea-waves (_BoU. delta Soc. Sism. Ital., vol. xiii.). 



2IOI, VOL. S2] 



