May 19, 1887] 



NATURE 



69 



20m., says that at disappearance it hurst into a suppressed 

 wer or halo of red ; and a third relates that it travelled from 

 to E. downwards, leaving two trains of sparks, and then 

 .Uy bursting into fragments. It looked like an immense fire- 

 k bomb, and many people, at the first impression, considered 



near as to mistake it for a large rocket. One observer 

 rs that as the meteor burst he found himself enveloped in a 

 'ave of heat" for several seconds ! 



'arefully comparing the descriptions of the path and direction, 

 > found difficult to determine with precision over what point 

 the earth's surface the fireball first became visible. Probably, 

 vever, this occurred above the English Channel, about 25 

 es S. E. of the Isle of Wight, when the height of the body 

 lid be about 70 statute miles. From thence it slowly pursued 

 irection to the N.N.W., and entered the English coast over 

 sport, after skirting the eastern boundary of the Isle of 

 ght. The meteor was descending to the earth at an angle 

 30° ; at Gosport its height was 50 miles, and it afterwards 

 sed over Winchester at an elevation of 38 miles, finally dis- 

 )earing a few miles north of Swindon, when its height had 

 :her decreased to 14 miles. 



rhis path apparently satisfies the majority of the observations, 

 there are, as usual, a few discordances. Thus, the Watford 

 ervation (Nature, May 12, p. 30) gives an altitude of 30° 

 end-point in the W. S. W. (magnetic bearing). This seems 

 too great ; about half, or 15°, would be consistent with the 

 er observations. At Staines, where the altitude must have 

 :n nearly the same as at Watford, it was given as 13°, and at 

 eral places in London the altitudes are mentioned as 17° 



1 less. Mr. Horner's observation at Montagu Street, W. 

 \TURE, May 12, p. 30) proves conclusively that the altitudes 

 -e very low. He saw the meteor first near 7 Geminorum 

 . 23°), and it disappeared after moving slowly in the direction 

 fupiter. If we adopt the end-point from this description £s 

 k)" -I- 16°, we get the terminal altitude as only 12°, which is 

 jxact conformity with the adopted height of 14 miles at dis- 

 )earance. The altitude of 17° from Highgate (Nature, 

 y 12, p. 30) is somewhat excessive, but it is well known that 

 estimates of this character the figures are nearly always too 

 at. Lieut. -Colonel Tupman states : "Most persons (as has 

 n often before remarked) guess altitudes at double what they 

 lly are, and ' the zenith ' means anything higher than 45° or 

 ' (see his paper on the great meteors of 1875, September 3, 

 md 14, Appendix, Astronomical Register, vol. xiv. p. i). 

 rhe observations at Staines, Hartfield, and Montagu Street, 

 , are very fairly consistent as regards the direction of the 

 teor, and, taken in combination with the especially valuable 

 lice from Stafford and the average of the Bristol observations, 



i radiant-point is found to have been situated in the S.S.E., 

 itude 30°, which is about 10° N. W. of Spica Virginis, or at 

 ! ° - 5'. No definite meteor-shower is known from this point 

 May, though Heis gives a position at 191° -t- 7° for April 18 

 May 18, which can hardly be the same. The great fireball 

 May 12, 1878, diverged from a radiant at 214° - 7°, and it 

 scarcely be associated with that of May 8 last, as the two 

 liants are 23° distant. 



The recent fireball had a real path in the atmosphere of 

 lUt no miles. Its motion was very slow, but there are great 

 :ordances in the various estimates of duration. A large pro- 

 tion of the observers only saw the latter part of the flight, 

 it would seem that the whole duration was fully 6 seconds, 

 bably more, in which case the velocity was certainly less 

 a 18 miles per second. The fireball, if moving in a para- 

 a, would have had a velocity of 13 miles per second. 

 Is to the actual size of this brilliant visitor, nothing can be 

 nitely concluded, because it is impossible to discriminate 

 ween the glare and flaming effect of the nucleus and what 

 nt of it represented the material diameter. The fireball was 

 bably a very diminutive body, and much smaller than its 

 spicuous aspect would lead us to suppose. Had it withstood 

 uption and dispersion during another \\ second, it would 

 e completed the remaining 28 miles of its path, and it must 

 e fallen to the earth near Winchcombe, in Gloucestershire. 



W. F. Denning. 



UNIVERSITY AND EDUCATIONAL 

 INTELLIGENCE. 



•XFORD. — We regret to hear that Prof. Prestwich has resigned 

 Chair of Geology which he has held for the last thirteen years. 



Cambridge. — Last week the grace authorizing the Vice- 

 Chancellor to enter into negotiation with Downing College with 

 a view to securing a site for the Geological Museum in the 

 grounds of Downing College, opposite the New Museums, was 

 carried by eighty to seventy-one votes. Prof. Hughes, in a 

 previous discussion, had objected to the site on the New Museum 

 grounds because it would soon become too crowded. The 

 Downing College site would afford plenty of room. Whether 

 the University and the College can agree on the question of the 

 price to be paid remains to be seen. 



The Botanic Garden Syndicate have issued a modified report, 

 proposing a different site for their necessary new plant-houses, 

 namely, palm house, stove, warm fern-house, and orchid-house, 

 and recommending that authority be given them to obtain a 

 detailed plan and estimate for building these, together with a 

 new propagating-pit, the cost not to exceed ^-yxxi. They also 

 strongly recommend the erection, in connexion with these 

 houses, of a small research laboratory. 



The examiners for the Adams Prize — the Vice-Chancellor, 

 Prof. Stokes, Prof. Darwin, and Lord Rayleigh — have given 

 notice that the subject for the Adams Prize to be adjudged in 

 1889 is "The Criterion of the Stability and Instability of the 

 Motion of a Viscous Fluid." It appears from experiment (see 

 Phil. Trans, for 1883, p. 935) that the steady motion in a tube is 

 stable or unstable according as the velocity is less or greater than 

 a certain amount ; and it is inferred from theory, confirmed by 

 experiment, that in two geometrically similar systems the motion 

 is stable or unstable according as ju/pcU is greater or less than a 

 certain numerical quantity n ; c, U being a length and a velocity 

 which define the linear scale and the scale of velocity in the 

 system, and p, fi the density and coefficient of viscosity of the 

 fluid ; but the quantity n has not hitherto been obtained even in 

 a simple case except by experiment. 



It is required either to determine generally the mathematical 

 criterion of stability, or to find from theory the value of « in 

 some simple case or cases. For instance, the case might be 

 taken of steady motion in two dimensions between two fixed 

 planes, or that of a simple shear between two planes, one at 

 rest and one in motion. 



Should the investigation not be found practicable for even a 

 simple case of the motion of a viscous fluid, some substantial 

 advance miojht be made in what has been done for a perfect 

 fluid (see Proceedings of the Mathematical Society, vol. xi. 

 p. 57), the title of the essay being modified accordingly. 



The prize is open to all Cambridge graduates. 



Each essay should be accompanied by a full and careful 

 abstract, pointing out the parts which the author considers to be 

 new, and indicating the parts which are to b3 regarded as of 

 more importance than the rest. 



The essays must be sent in to the Vice-Chancellor on or 

 before December 16, 1888, privately. Each is to have some 

 motto prefixed, and to be accompanied by a paper sealed up, 

 with the same motto and the words Adams Prize on the outside, 

 and the candidate's full name, with his College and degree, 

 written within. The papers containing the names of those 

 candidates who may not succeed will be destroyed unopened. 

 Any candidate is at liberty to send in his essay either written 

 (but not in his own hand) or printed or lithographed. The 

 successful candidate receives about ;^I70. He is required to 

 print the essay at his own expense, and to present a copy to the 

 University Library, to the Library of St. John's College, and to 

 each of the four examiners. 



SCIENTIFIC SERIALS. 



The Quarterly yournal of Microscopical Science for March 

 1887, vol. xxvii. Part 4, contains : — On the termination of nerves 

 in the liver, by A. B. Macallum (plate 36). These researches 

 were made on the livers of man and Menobranchus (Necturus) : 

 the liver cells of the latter are from two to four times the dia- 

 meter of those in man, and so were very favourable for these 

 investigations ; in man fibrils from the intercellular plexus of 

 nerves give off excessively minute twigs, which terminate each in 

 a delicate bead in the interior of the hepatic cells, near the 

 nucleus ; in Menobranchus the simple intracellular nerve-twigs 

 always terminate in the neighbourhood of the nucleus, either 

 singly or after branching, each terminal point being a delicate 

 bead.— On the nuclei of the striated muscle-fibre in Necturus 

 {Menobranchus) lateralis, by A. B. Macallum.— The develop- 

 ment of the Cape species of Peripatus, Part 3 : on the changes 

 from Stage A to Stage F, ,by Adam Sedgwick, F.R.S. (plates 



