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observed some remarkable coincidences between the travelling of positive electrical disturbances through the transatlantic cables (in the construction and working of which he was concerned), and the occurrence of earthquake shocks in the North of England.
These and other observations led him to suppose that some earthquake shocks are due to subterranean lightning, a rather startling, and at first thought a somewhat paradoxical, hypothesis. This first impression is strengthened by the nauseating prevalence of the silly practice of blindly attributing to electricity everything that is at all mysterious, a practice that prevails in direct proportion to the ignorance of the whole subject.
Varley's speculations are totally different from this sort of idle prattling in mere words. He shows that the outer crust of the earth is saturated to variable depths with water, and consequently forms a shell or coating—like the tinfoil of a Leyden jar—which is a conductor to electricity of high tension. Mr. Varley assumes that between this and the inner fused material of the earth there exists a layer of dry non-conducting rock, corresponding to the glass of the Leyden jar.
Fused rock being a conductor the analogy to the original Leyden jar is completed; there is the inner conductor, the outer conducting film, and the intervening non-conductor. I say the "original” Leyden jar, as this was filled with water up to the level of the outer tinfoil, the water doing the work of the inner coating of tinfoil of the modern form of apparatus.
What happens when a Leyden jar receives an overcharge, either on its inner or outer coating ? Simply a "disruptive discharge” violently and noisily proceeding through the intervening glass.
The cables under Mr. Varley's observation indicated the charge received by the outer coating of the terrestrial apparatus, and assuming this to be of sufficient intensity, it must somewhere, at a region of least resistance, break violently through the dry solid stratum, which it would do the more easily seeing that this is by no means so resistant as glass.
I may add that the experience of coal and other mining verifies Mr. Varley's theoretical assumption of the existence of a dry and solid substratum ; below a certain depth the water-bearing strata are passed and the workings become dry and dusty.
My first experience of earthquakes was in the autumn of 1842, when making a pedestrian trip in the Highlands, in company with two fellow-students from Edinburgh. On arriving at Crieff from Comrie we found the people greatly alarmed at a shock they had felt VOL. CCLVIII. NO, 1853.
about half an hour before, though we had not observed it. Somewhat later, when rounding Loch Tay on our way to Loch Rannoch, we were startled, not by the trembling of the earth, which we expected and had been studiously seeking to observe, but by an unexpected roar of subterranean thunder, which appeared to commence almost under our feet and to die away under the distant mountains. There was no agitation of the waters of the lake, no shock that we could perceive, though we learned afterwards that a slight shock had been felt by people indoors.
The disproportion of the noise to the tremor in this instance is better explained by Varley's theory than by any that are inore prevalent.
If I remember rightly, Mr. Varley did not insist upon applying his theory to the explanation of all earthquakes. It certainly is not applicable to those which accompany volcanic eruptions. The explanation of these is simple enough ; but not so the frequent tremors that have no traceable connection with volcanic action.
The fact that this class of earthquake is so much more frequent in tropical and subtropical regions, where atmospheric electrical storms are so much more violent, favours Mr. Varley's theory. The most active and the greatest volcanic focus of Europe is Iceland, but it is not by any means correspondingly subject to earthquakes.
DARWINIAN BEEF. THE primary facts upon which Darwin based his argument on
1 the possibilities of natural selection were those presented by the known results of artificial selection ; these coming fully within the grasp of human experience. Among those who were the most sincerely alarmed by the imagined subversive consequences of the Darwinian heresy were our comfortable country squires. Like the perpetually quoted M. Jourdain and his prose, these bucolic representatives of untainted British conservatism were then, and had been for some time past, the most efficient and persistent of Darwin's supporters ; they were devoting their best efforts to demonstrate the fundamental principle of Darwin's heresy, the mutability of species by means of selective breeding.
All the cattle shows, poultry shows, dog shows, horse shows, root shows, seed shows, prize vegetables and flower shows, were and are a series of popular and triumphant Darwinian demonstrations, mainly supported most innocently and unconsciously by those who regarded Darwin as ambassador-plenipotentiary of the devil.
By the commercial evolution of any variation among domestic animals and cultivated plants that the caprice of the market may demand they have proved how utterly baseless is the old dogma of the persistency of specific characters.
The report of Dr. Sprague on “marbled beef” assures us that cattle-breeders can manufacture this novelty if the public will purchase it, and speaks of rearranging the distribution of fat and lean as freely as a manufacturer of wall papers, or a calico printer, may rearrange his blocks to bring out new patterns for the forthcoming season. As the Times remarks: “ The stock-yard has become a sculptor's studio, in which living matter is moulded according to the artist's discretion.”
Instead of placing the fat of our prize cattle in huge unmanageable lumps as heretofore, we are to have it regularly interlarded with the muscular fibres and fascicules, forming marbled, riband-patterned, streaky beef; and this is to be effected by scientific feeding, and the survival of the fittest : by faithful and vigorous application of Darwinian principles.
The Times tells us that “ the most splendid marbling is as fleeting as beauty in general, and will not survive discomforts,” that the marbled cattle must not be subjected to the hardships of a sea voyage, and, therefore, we must do our marbling at home. This conclusion, however, is liable to serious modification now that the problem of importing slaughtered meat in prime condition has been practically solved.
THE CONSTITUTION OF CLOUDS. “ VJESICULAR VAPOUR” is a term that still remains in
scientific treatises. It expresses the assumption that clouds and the white cloudy matter artificially produced when steam is ejected into the air are composed of minute vesicles like soap bubbles.
Tyndall (“Heat considered as a Mode of Motion”) says: "Clouds float in the air, and hence the surmise that they are composed of vesicles or bladders of water, thus forming shells instead of spheres. Eminent travellers say they have seen these bubbles, and their statements are entitled to all respect.”
If I remember rightly it was De Saussure or De Luc who described such vesicles, seen on a mountain top, having dimensions comparable to nustard seeds. Both of these observers were satisfied of their existence, and to De Saussure we are indebted for the above-quoted name.
In "Nature" of March 12 is an illustrated description of the
“ Cloud-glow apparatus” of Prof. J. Kiessling. Among other results obtained by his method of observing suspended atmospheric matter was a demonstration that the particles of so-called vesicular vapour are not altered in dimensions by rarefaction of the medium in which they are suspended, which would be the case were they vesicular. He tests this by observing the diffraction phenomena that depend on the size of particles. These were not changed with the rarefaction.
A more direct demonstration was made by M. J. Plateau about fourteen years ago. By means of a tube drawn to a very fine point he obtained actual vesicles or hollow water bubbles, of less than a millimetre in diameter, and he passed these to the free under-surface of water in a tube.
In every experiment the water skin of the bubbles united with the water in the tube, and the enclosed air rose to the surface. When a large number of such bubbles was thus introduced they formed a cloudiness in the water as they gradually rose to the surface.
On submitting the so-called vesicular vapour to the same test, M. Plateau found that it was all condensed, and added to the bulk of water in the tube without producing any such cloud of air particles as should have been there had the cloud-matter been constituted as De Saussure stated.
There still, however, remains the possibility that under somie circumstances (say at great elevations, with cold and rarefied surroundings) a particle of condensed water, subjected to free solar radiations, might, by internal absorption of heat and external cooling by contact and evaporation, become filled with aqueous vapour derived from itself, and thus expanded into a bubble.
Professor Kiessling's experiment omits the action of energetic radiation, which is the probable cause of the vesicular structure, if such exists. With the apparatus at his command in the Royal Institution, Dr. Tyndall might put this question to the test.
W. MATTIEU WILLIAMS.
THE extent to which Christian ceremonial and popular custom
are influenced by Pagan practice is one of the most interesting subjects with which the historian or the student of folk-lore is concerned. That the Church adopted so many of the pagan institutions as had struck deep into the people and were capable of receiving an ecclesiastical veneer, and that the public with the connivance rather than the consent of the Church preserved other practices of their primitive faith, are matters now conceded. Among other things, however, that have disappeared in consequence of the friction brought with increased facilities of travel are old customs, and a man must now go far afield to find any but the most modified traces of pagan worship. It is interesting, accordingly, to find in “ The Cyclades ” of Mr. J. Theodore Bent,' whose name is not unfamiliar in these pages, an account of the superstitious practices that still linger in the islands of the Ægean. Here the graceful faith in the Nereid still survives, and when a man catches cold sleeping under a tree, he spreads beneath it, to conciliate the Nymph, a clean white cloth, with new-made bread, honey, wine, &c., not forgetting a pot of incense. Elias the prophet has, Mr. Bent shows, some of the attributes of "HAcoç, the sun deity. St. Anarguris receives worship of a kind previously accorded to Pan; St. Dionysius is the successor of Dionysos or Bacchus; and St. Nicholas the lineal descendant of Poseidon or Neptune.
DEATH OF KING HAROLD.
L EW things are more remarkable than the reluctance of a section
T of the public to believe in the death of characters of exceptional eminence. Through centuries the idea prevailed that King Arthur, assuming him for the nonce to have been a real character, would return and redress the wrongs which his Round Table had left
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