5«2 



NATURE 



{Oct. 12, 1882 



the Thames." A mile to the west at Highbury, other 

 molluscan genera are represented. A list of the Highbury 

 shells is given by Dr. John Evans—" Stone Implements." 

 p. 524- "S^ 



I now come to the bed of gravel indicated at b (Fig. 1) 

 and a (Fig. 4). It is found at an average depth of 12 feet, 

 and descends to 20 or 30 feet from the surface ; this drift 

 contains, chiefly in its upper parts, lustrous sub-abraded 

 Palaeolithic implements of medium age. All these tools 

 have been more or less moved and relaid by the agency 

 of water ; none are quite unabraded ; bones, teeth, and 

 tusks of the mammoth also occur, with other mammalian 

 remains, driftwood, &c. This deposit has been described 

 by Prof. Prestwich in the Quarterly Journal of the 

 Geological Society, 1855, vol. x '- P- I0 7- The material is 

 remarkable for containing immense blocks of sandstone, 

 probably never moved by water alone, and sometimes 

 weighing one, two, or more hundredweights ; that these 

 stones fell from blocks of drifting ice seems extremely 

 probable. Some of them measure two feet across, and 

 they must have been brought from the north long prior to 

 the deposition of the trail, and probably long after the 

 time when other immense blocks found at 20 feet and 30 

 feet at the bottom of the gravel were deposited. Some 

 show glacial striae. Generally in the deepest pits, the 

 third and oldest class of implements is found, the examples 

 are rudely made, massive, deeply ochreous in colour, with 

 a thick ochreous crust, the ochreous tint not derived from 

 the matrix they are now in ; they are generally very much 

 abraded, indicating transport from a long distance, or 

 long dashing about in water with other stones, but as the 

 three different classes of implements will be illustrated in 

 my concluding note, and proved to be of totally distinct 

 ages, far removed from each other, I need not refer to 

 them at length here. 



It commonly happens, that the higher the gravels above 

 the present rivers, the older they are, but here we have 

 an instance where the newer gravels and more recent 

 implements are from 8 feet to 26 feet higher than the 

 old. WORTHINGTON G. SMITH 



THE COMET 

 'PHE Astronomer-Royal has received, through Sir 

 -*• James Anderson, a telegram from Mr. Gill, in the 

 following terms : — " Please inform Astronomer-Royal 

 that comet's declination in my letter of September 1 1 

 should be 56 minutes 30 seconds south. Sudden disap- 

 pearance of comet at ingress on sun's disc observed 

 September 17 days 4 hours 50 minutes 58 seconds Cape 

 mean time. Comet not visible on sun." Mr. Gill's 

 remarkable observation is without a precedent, and an 

 extraordinary illustration of the intense brilliancy which 

 the comet attained at perihelion. 



The Emperor of Brazil telegraphs thus to the Academy 

 of Sciences of Paris;— "Rio, 26 Septembre, ioh. 20m. 

 Note Cruls. Grande comete australe visible de jour 

 observee aujourd'hui. Queue 30 . Presence sodium et 

 carbone. 25 Septembre. — Visible de jour au sud de 

 Rio 18, 19, 20. Vue par moi aujourd'hui de 4h. 10m. a 

 5h. 40m. matin. Splendide 26." 



Mr. Ainslie Common, of Ealing, whose daylight obser- 

 vations on September 17 may have an important bearing 

 on the theory of the comet, has furnished us with the 

 following extract from his note-book on that date : — 

 " 10.45. Found bright comet. S.W. sun. Value. 



10.59. Cornet precedes sun, 6m. 5c s., centre to centre 1 



::} 



1 1. 10. Comet south, sun's limb, 20R 50D = 18' S" 



11.47. Comet precedes sun, 5m. 48s. (?) 



II.58. Comet south, sun's limb, i6k 6od = 14' 41' 



12.0. Comet precedes sun, 5m. 44s. (good) \ 



12.6. Comet south, sun's limb, 15R 55D = 13' 45"... J 



Clouds came over shortly after this." 



Mr. Common has corrected an error in reducing the 



last micrometrical difference'of declination into arc : one 

 revolution = 53"'i. He states that he made an immediate 

 attempt to telegraph to Greenwich and Dun Echt, but the 

 office at Ealing was unfortunately closed. 



We have received several drawings from M. Bulard, of 

 Algiers, showing the appearance of the comet as viewed 

 with the naked eye, in one of which the tail is depicted 

 with considerable curvature. Also a sketch of the head 

 as seen in a powerful telescope, exhibiting the system of 

 envelopes rising from the nucleus, which has characterised 

 several recent bright comets (see Figure). 



The following elements of this comet have been calcu- 

 lated by Mr. Hind from the Dun Echt and Coimbra 

 meridian observations on September 18, a meridian ob- 

 servation at the U.S. Naval Observatory, Washington, on 

 September 21, and an observation made at the Collegio 

 Romano, at Rome, on the morning of October 2, obligingly 

 communicated by Prof. Millosevich : — 



Perihelion passage, September I7'2l69, Greenwich M.T. 



Longitude of perihelion 276 14 36 1 Apparent 



,, ascending node 346 6 58 > equinox 



Inclination 37 58 59 ) Sept. 25. 



Logarithm of perihelion distance ... 7'9o6527 

 Motion — retrograde. 



These elements afford further indication of disturbance 

 of the comet's motion near the time of passage through 

 perihelion. At the moment when Mr. Gill observed the 

 comet upon the sun's limb, when the distance from the 

 sun's centre was consequently i6'"o, the orbit gives the 

 central distance, as io''9, or the comet projected upon 

 the sun's disc. Considering that Mr. Gill's observation 

 was made less than one day previous to the accordant 

 meridian observations at Dun Echt and Coimbra, it is not 

 easy to see how such difference could arise from error of 

 elements, which represent the middle position employed 

 in their determination within a minute of arc. 



The following expressions for the comet's heliocentric 

 co-ordinates x,y, z, referred to the equator, are to be used 

 in connection with the X, Y, Z of the Nautical Almanac, 

 in the calculation of geocentric positions : — 



