April 23. 1896J 



NA TURE 



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need of most of these small museums is an adequate and settled 

 annual income sufficient to defray the cost of intelligent manage- 

 ment. Capital sums for building, fittings, &c., would flow in, 

 and donations of good local collections would often be made, if 

 the fear of " want of permanence" could be allayed. It is this 

 which is the difficulty in the management of local museums in 

 the vast majority of cases, and a moderate grant of "technical 

 instruction" funds in a county would often give far better 

 results, educationally considered, than many of the objects to 

 which this money is now applied. 



The matter is by no means political or controversial — such 

 grants would benefit many deserving institutions ; and I hope 

 that all well-wishers of museums will use their influence to get 

 such a clause as that above indicated inserted in the Bill when 

 before Committee. I -commend the subject to the Museums 

 Association and to the Secretaries of local scientific societies as 

 one in which their energies would be most usefully exercised. 



C. 



A Bright Meteor. 



We had the good fortune to witness a splendid meteor 

 here on Sunday evening, the 12th of this month. The sky was 

 perfectly clear, the hour 8 p.m. The lady with whom I was 

 walking, by an exclamation called my attention to it, so that I 

 did not see it on its first appearance, but it must have started 

 from the neighbourhood of a Draconis ; it then pursued a 

 south-easterly course, passing nearly parallel to C a-"<i t? Ursa; 

 Majoris and a Bootis or Arcturus, and disappearing at last 

 behind a hill to the east. We did not, therefore, see its ter- 

 mination ; but I hear from others who did, that there was no 

 explosion. It must have taken several seconds in its flight, as 

 there was time for my companion to make several remarks. Its 

 size was very considerable, and its light intermittent. Three or 

 four times it seemed as if about to be extinguished, but again 

 blazed forth ; the colour was a fine yellow, changing to crimson ; 

 a train of sparks followed it of about 5° in length. The 

 whole path traversed could not have been less than 50°. In the 

 evening twilight not many stars were visible, so that I was 

 unable to determine its exact course as accurately as I could 

 have wished. J. D. La Touche. 



Stokesay Vicarage, Craven Arms, Shropshire, April 14. 



It may be of interest to record the appearance of a fine 

 meteor, the finest I remember to have .seen, on the evening of 

 Sunday, April 12, about 8.6 p.m. I was standing in a field in 

 the parish of Mathon, on the extreme western border of 

 Worcestershire, when a friend who was with me drew my at- 

 tention to it. The meteor was then about 20° E. of N., and 

 roughly half-way between horizon and zenith. It passed down- 

 wards and eastwards, very slowly as it seemed to us, till it 

 reached a spot about 30° N. of E. , and perhaps 20^ above the 

 horizon, when it disappeared. Its course was right underneath 

 the Bear, which, lying east of the pole-star, was just becoming 

 visible at the time. The time during which we watched the 

 meteor I should estimate at from 10 to 15 seconds. The 

 meteor consisted of a bright head appearing many times as 

 large as Jupiter, and a train like a rocket's, but much shorter 

 in proportion. The night, in the intervals of fierce north- 

 westerly squalls, was exceptionally fine and clear. 



West Malvern, April 16. A. G. Tansley. 



A Daylight Meteor. 



Ai 7.25 a.m., April 18, a meteor was observed by an inmate 

 of my house. The sun was shining clearly in an almost 

 unclouded sky when, in looking up, three bright stars were seen 

 in rapid succession shooting over the trees in a northerly 

 <lirection. The person who made the observation was much 

 excited with the sight, never having witnessed fire-balls of such 

 brightness, and rapidity before. James Shaw. 



Tynron, Dumfriesshire. 



" Rana esculenta" in Kincardineshire. 

 When on a brief visit to Kincardine.shire last month, I was sur- 

 prised to find R. esculenta in considerable numbers at a few places 

 which I visited. I found the frogs in pools beside the Bervie, 

 and al.so in places several miles away. One of these was a small 

 isolated bog. Mr. George Sim, of Aberdeen, who is well 

 cquainted with the fauna of Kincardineshire, was unaware of the 

 I xistence of this frog in the county until I called his attention 



to it. In 1837 and 1842 large numbers of these animals were 

 introduced into England, but I have not heard of a similar 

 introduction into Scotland. It does not seem probable that the 

 frog .should itself have migrated so far north. When a thorough 

 examination of the district has been made, it may be found that 

 the animal is widely distributed. Philii' J. White. 



University College of North Wales, Bangor. 



THE RONTGEN RA YS. 



THE investigations of M. Henri liecquerel on the 

 radiation emitted by certain salts of uranium have 

 shown the existence of a kind of radiation intermediate 

 in its properties between light and the Rontgen rays. 

 These investigations are exceedingly interesting on 

 account of the differences as well as the analogies they 

 disclose between the uranium radiation and the Rontgen 

 rays. M. Becquerel has shown that the radiation from 

 the double sulphate of uranyle and potassium is analogous 

 to Rontgen rays, inasmuch as it can affect a photographic 

 plate after penetrating substances such as aluminium, 

 copper, wood, &c., which are opaque to ordinary light ; 

 it also resembles these rays in being able to discharge an 

 electrified body, whether the charge be positive or 

 negative. On the other hand, it differs from Rontgen 

 rays and resembles ordinary light, inasmuch as it can be 

 refracted and polarised. It is also much more easily 

 reflected than Rontgen rays. The radiation from the 

 uranium salts is thus mtermediate in properties between 

 ordinary light and Rontgen rays ; and as there can be no 

 question but that this radiation consists of transverse 

 vibrations, inasmuch as it can be polarised, it affords 

 strong presumptive evidence that the Rontgen rays are 

 also due to transverse vibrations. 



The persistence of the radiation from the potassium 

 uranyle sulphate is very remarkable. M. Becquerel found 

 that crystals which had been kept in the dark for 

 160 hours continued to radiate vigorously. This radiation 

 is absorbed almost equally by aluminium and copper, so 

 that it does not show the same dependence upon the 

 atomic weight of the absorbing medmm as that of the 

 Rontgen rays ; on the other hand, the radiation resembles 

 Rontgen rays in not being homogeneous. 



With respect to direct evidence of the Rontgen rays 

 being due to transverse vibrations, such as would be 

 afforded by a difference between the absorption by two 

 plates of tourmaline (i) with their axes parallel, (2) with 

 their axes crossed, the results are somewhat conflicting. 

 On the one hand, Prince Galitzine and M. de Karnojitsky 

 get a greater absorption through two plates of tourmaline 

 when their axes are crossed than when they are parallel ; 

 while, on the other hand, M. H. Becquerel, M. Sagnac, 

 and the writer get no appreciable difference between the 

 two cases. It is just possible that as tourmaline is a 

 mineral which varies greatly in chemical composition, 

 those varieties which contain abnormal quantities of the 

 heavier metals may show this effect, whilst in other 

 specimens it may be too small to be appreciable. 



A considerable number of experiments have been made 

 to find the part of the tube where the Rontgen rays 

 originate. Perrin, using pin-hole photography, came to 

 the conclusion that they arise at the places where the 

 kathode rays strike against a solid obstacle. Rowland, 

 Carmichael and Briggs, on the other hand, using a very 

 highly exhausted tube with the terminals only one milli- 

 nietre apart, located the origin of these rays at the ex- 

 tremity of the anode. Prince Galitzine and M. de Karno- 

 jitsky place the origin inside the tube some millimetres 

 behind the glass. The writer, with the assistance of 

 Mr. McClelland, investigated this point by measuring 

 the rate at which electricity leaks through an air space 

 of fixed length at different distances from the bulb ; the 

 Rontgen rays passing through a small hole in a thick 

 plate of metal. The rates of leak were found to vary 

 inversely as the square of the distance from a point, but 



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