August 3, 1893] 



NATURE 



317 



ent circumstances, and I observed a phenomenon that appears 

 to me to be of interest. 



On July 10 I was on the Matterhorn in very doubtful weather. 

 It appeared as though the Fohn (or southerly wind) were 

 struggling with a northerly wind, and as though the former 

 conquered. Clouds or mist pressed up from Italy, and rose 

 higher and higher, covering the other mountains before the 

 Matterhorn. We had some snow at intervals even before mid- 

 day, and by the time that we had, on return from the summit, 

 descended as far as the upper hut, it was snowing steadily. I 

 think that, as regards the Matterhorn, the electrical hissing of 

 ice-axes, rocks, &c., began about 3.30 p.m. or 4 p.m., and 

 lightning began rather later. 



At last came one flash, apparently very near to us, the 

 thunder following close with a crash. Before the thunder, 

 however, and apparently xuith the flash, came a curious split- 

 ting, cracking, and shivering sound, with a kind of "splash" 

 from the rocks — as it seemed. I give many adjectives for want 

 of one good expressive word. This sound preceded the thunder, 

 and was both sharp and faint ; I felt that I only heard it 

 because I was on the spot. 



Later, another flash came close to us. This time I heard no 

 "splash" from the rocks ; but, apparently 'Jjith the flash, and 

 before the thunder-crash, there came a light, shivering, 

 branching crack again, something like the "ghost "of thunder, 

 one might say. It reminded me this time of the shiver that 

 passes over the surface of new snow, only very slightly crusted, 

 when first broken in any part by the feet of a traveller. (Some 

 climbers will know this sound ; but I myself have only 

 occasionally noticed it, and that only when I have been the 

 first on a snowfield soon after a heavy fall of snow. ) I received 

 a slight shock in the head this time. A third flash gave the 

 same sound as the second ; but no others seemed so close, and 

 I never heard this sound again. 



It was dark when we reached the lower hut ; and all down 

 the arele the brushes of purple light that streamed from our 

 fingers (when held up) and from our axes, hats, hair, &c., were 

 very beautiful. The fingers gave better brushes when wetted. 

 There were numerous brushes streaming from the rocks, these 

 being wet with water melted from the snow. 



Some other people who were on the Gorner Grat the same 

 day told me, before 1 mentioned my experiences, that the 

 lightning seemed to give a splashing sound on the rocks. They 

 also told me that those who wore felt hats, felt return shocks, 

 while those with straw hats did not. All the hats were wet. 



So much for observation ; now for a theory. 



To begin with, since the thunder distinctly crashed after the 

 lightning-flash, it would seem that the phenomenon that caused 

 the sound I heard must have preceded the spark. 



I would suggest the following explanation. 



I do not think that those who have never been actually in a 

 storm realise how very indefinite, in substance and boundai-ies, 

 "a thundercloud " is. It seems certain that we must not 

 regard it as if it were a polished conductor that is gradually 

 charged until it sparks to earth or to other clouds. More prob- 

 ably there is a fall (or rise) of potential through the substance 

 of the cloud itself. When the stress is too great, there is 

 probably a breakdown along many paths in the form of the 

 fine branching sparks observed when a Wimshurst is used with- 

 out a condenser. This preliminary breakdown suddenly gives 

 a very much larger potential-difference between the portion of the 

 cloud-masses towards which it takes place ; so suddenly in fact, 

 that a spark-discharge occurs before more diffuse modes of read- 

 justment can obtain. It seems to me that it is only by some such 

 preliminary discharge from behind that such irregular "surfaces " 

 as those of clouds could attain the condition requisite for the true 

 spark. In something the same way we can pass a spark 

 between two rough or pointed metal terminals by a sudden 

 discharge through them, while we could not raise them in any 

 slower way to the necessary condition. 



According to this view, a slighter and more branching dis- 

 charge in the body of a cloud would be the necessary prelimin- 

 ary to a regular flash ; and the, relatively faint, sound of it 

 would precede the " thunder" of the final flash. When once 

 the flash occurs, resistance is much diminished, and the stress 

 of the whole region is relieved through the path created. 



An obvious objection to this view, however, will occur to 

 many. " Would the time-interval be long enough? Would 

 not the first sound be practically heard with the thunder, and 

 be drowned in it ? ' 



Another explanation might be, that (as is often the case 

 NO. 1240, VOL, 48] 



with a Wimshurst or other machine) there are fainter, tenta- 

 tive, branching discharges that precede the bright spark. But, 

 if this were the case, they should surely be heard in some cases 

 before any spark occurs at all. 



Finally, the sound, though it appeared to come out of the 

 air, might have been due to the movements of the stones and 

 rocks over the surface of the mountain, occurring when the 

 stress was relieved. Such a sound might well reach one before 

 the sound of the spark. WALTER Larden. 



R. N. E. College, Devonport, July 24. 



Highest Rainfall in Twenty-four Hours. 



With reference to the paragraph quoted in your notes of this 

 week's Nature from the Indian Planters' Gazette of Jan. 28, 

 1893, the most elementary knowledge of Indian meteorology 

 would suffice to show that the remarkable figure, 48 inches, 

 supposed to represent the fall of a single night in January at 

 Dehra Dun, is simply a misprint for 4-8. The entire rainfall 

 of the winter season in no part of India exceeds one-half this 

 amount, and I have no hesitation in declaring such a figure as 

 48 inches in twenty-four hours to be absolutely without prece- 

 dent, and, in my opinion, so extraordinary at such a season, 

 that, if it really were 48, it would require us to regard all exist- 

 ing Indian meteorological data with suspicion. Thirty inches 

 in twenty-four hours has often been recorded at Chirapunji in 

 June and July. Can any one show a single instance of even 

 20 inches in twenty-four hours at Dehra Dun ? 



Moreover, the whole annual supply at Dehra Dun is only 

 75 inches, while that of Chirapunji is 600 inches ! 



July 29. E. Douglas Archibald. 



Vivisection. 



The recent remarkable discoveries in connection with 

 Myxcedema conclusively prove the value of vivisection as a 

 means whereby human suffering may be alleviated, and only 

 those who are blinded by ignorance or prejudice would dare 

 deny that hundreds of sufferers from goitre, and other distressing 

 symptoms of cretinism, have obtained relief solely through ex- 

 perimental research upon animals. Inconsistency is closely 

 linked to prejudice, and the greatest anomaly is the Anti-Vivi- 

 sectionist who, while objecting to the alleviation of human 

 suffering on the score of " cruelty to animals," enjoys and 

 countenances, for the gratification of his or her own individual 

 pleasures, the most horrible cruelty and torture to helpless 

 creatures. Only a few of such cases now occur to me, and these 

 I herewith append, but there are many others as disgustingly 

 cruel. 



Boiling lobsters, prawns, etc., alive. 



" Whitening and tendering " veal by bleeding, and beating 

 with sticks, the cM while still Jiving. 



Skinning and cooking eels alive. 



Maiming, and shattering to pieces, pigeons and other birds 

 ("sport"), hundreds dying a lingering death. 



Hacking and mauling rabbits by gins. 



Hounding to death harmless hares, and exulting over this tor- 

 ture ("sport"). 



Plucking feathers from living birds, and skinning living 

 animals. 



When every professed anti-vivisectionist undertakes to endeav- 

 our to put a stop to these, and similar cruelties, their sincerity 

 will at least be visible. 



Bournemouth, July 24. Cecil Carus-Wilson. 



A Correction. 



In my "Preliminary Note," as read at the Royal Society 

 meeting, June 15 last (Nature, vol. xlviii. p. 311), the first para- 

 graph reciting "The laws connecting pairs of axes, by succes- 

 sive rotations round which a given displacement of a rigid body 

 in space may be effected," should read: "If the first axis is 

 taken arbitrarily in a plane parallel to that of the ' central 

 axis,' and any given direction f' meeting it, to which latter the 

 axis remains parallel, there is a direction determined to which 

 its conjugate must be parallel, in the side common to three 

 quadric cones the constants of which are functions of f ' and the 

 vectors defining the displacement and the position of the first 

 axis." 



The next two paragraphs will require slight modifications 

 accordingly ; and the last will, of course, be unnecessary. 



I owe this correction to a correspondence with which Prof. 

 W. Burnside, F.R.S., has favoured me since the meeting. 



July 29. J. J. Walker. 



