6o2 



SCIENTIFIC NEWS. 



[June 29, 18 



department of the Loire, where the temperature of the 

 air was 79° Fahr. That of the hailstones was i8J° 

 below the freezing point. 



We have many records of coloured hailstones. (See 

 Nature, May 21st and September loth, i?,2,^, Philosophical 

 Transactions, No. 203, etc., for examples.) Their colours 

 were red, brown, and grey, and the colouring matter 

 appears to have been oxide of iron, but reliable analyses 

 are wanting. The flaming hydrogen projected in the 

 solar prominences must terminate in aqueous vapour 

 mixed with metallic vapours, chiefly iron ; but what 

 finally becomes of such mixture must depend on the 

 velocity of ejection. The measured velocity of some pro- 

 minences proves to be sufficient to ejectits material beyond 

 the distance of the earth's orbit. Such vapour, while 

 directly exposed to solar radiance, would probably remain 

 in gaseous condition, but if the earth's shadow should 

 sweep into any of it, condensation into solid particles must 

 immediately take place, and such particles would fall 

 upon the earth, carrying with them any other materials 

 with which they might be associated. 



Another theory has been more recently put forward by 

 M. Andries, who ascribes the formation of hailstones to 

 ascending whirlwinds. We know that such ascending 

 whirlwinds do exist by the fact that dust is some- 

 times carried upwards in considerable quantities, but we 

 do not yet know the upper limit of such ascending action. 

 Assuming it to be considerable — say three or four miles 

 — and that warm air saturated with aqueous vapour is 

 carried to such a height, its sudden expansion must be 

 attended with sudden cooling, and under certain condi- 

 tions — as at night, for example — the cooling would 

 effect condensation into ice particles, hoar frost or snow, 

 which by the whirling might be aggregated into hailstones. 

 This action is similar to that which I have described 

 above, but of a more exceptional and limited nature. 



In working out the rationale of this subject we must 

 not fail to give proper weight to a fact which is too often 

 overlooked, and which at first glance may appear paro- 

 doxical, viz., that as we ascend to rarer and colder 

 regions of the upper air the intensity of the heating 

 power of the solar rays increases. But these rays can- 

 not do the work of heating unless there is something to 

 be heated. In passing through empty space or diather 

 manous matter thej' do nothing but go on. 



In the course of an ascent of Mont Blanc I made an 

 instructive experiment to illustrate this. During the first 

 day's chmb the skirts of my coat were wetted by falls 

 on the sloppy glacier. At night on the Grands Mitlets 

 they were frozen, and when I came into sunshine on the 

 Grand Plateau the sunward side speedily thawed. This 

 suggested the experiment of turning round like a joint 

 roasting before a fire. On doing this very slowly I was 

 alternately frozen and thawed on all sides, as they fell 

 in shadow or sunshine, and the ice on my coat tails was 

 in the form of sparkling crystals. 



Some of my readers will doubtless find objections to 

 Schwedoft's theory. I know beforehand what these 

 objections are likely to be, and will discuss them in my 

 next, especially the " manifest absurdity " of Sir William 

 Thomson. 



. — ♦^«t^<^«f-» — 

 Anesthetics in China. — It appears that in China 

 prison officials sell to the persons in their charge pieces 

 of an anaesthetic soap, to be chewed before or during the 

 torments applied both to the suspected and to the 

 convicted. 



THE NEW RINGS OF SATURN, OUTSIDE 

 OF THOSE PREVIOUSLY KNOWN. 



IT is known that besides the two principal rings, 

 always visible, Saturn possesses a third which re- 

 mained for a long time unperceived by reason of the 

 feeble lustre of its nebulous matter, and which is not 

 visible even with the sixteen centimetre refractor ot 

 the Observatory at Grignon. 



Bej'ond these known rings, the attention of Dom 

 Lamey has been frequently and spontaneously drawn 

 for about twenty years to certain ring-shaped lights 

 visible between the regions in which revolve Mimas and 

 Titan, the first and the sixth satellites of the Saturnian 

 system. These rings, which are lost in the zone of illu- 

 mination surrounding Saturn, are but very rarely seen in 

 their entirety. According to a communication recently 

 made by Dom Lamey to the French Academy ot 

 Sciences, these rings are generallj' more luminous on one 

 side, which varies in position ; the chief lustre generally 

 coincides with the nearest satellite, but often surpasses it 

 in intensity. 



The first observation of these rings dates back to- 

 August 2nd, 1868, when he recognised them at Stras- 

 burg with a small equatorial of ten cm. aperture. Sub- 

 sequently he tried to re-discover them at Dijon, with the 

 same instrument, but unsuccessfully. It was only on 

 February 12th, 1884, when installed on the summit of 

 Grignon, in the midst of a very clear atmosphere, and 

 furnished with a more powerful instrument, that he was 

 able again to distinguish these lights, which then pre- 

 sented themselves in the form of perfectly definite rings. 

 Up to the date of his memoir (June 5th, 1888) he is only 

 able to produce nineteen sketches of these rings, because 

 he had remained for a long time undecided as to the nature 

 of the phenomena observed. But he has since been con- 

 vinced that they cannot be produced by anything in our 

 atmosphere nor by the instrument employed, the images 

 having never changed their form or relative position on 

 examination with objectives of different apertures and 

 focal lengths, fitted with eye-pieces sometimes positive 

 and sometimes negative, and giving various magnifying 

 powers up to 250 at least. Nor can these rings be due 

 to any illusion produced by the eye or the imagination, 

 since two of his colleagues, Dom Et. SifFert, and Dom Fl. 

 Demoulin have also seen and sketched them, agreeing 

 with him as to their form and the position of the maxi- 

 mum of lustre, and that in a quite spontaneous manner. 



These rings are four in number, if we count as such 

 the luminous zone bordering the exterior of the outer 

 ring. This zone has been observed only on the side 

 which is turned towards our planet. It is generally 

 nebulous, but it frequently becomes resolvable into a crowd 

 of small luminous points, scattered along an eUiptical arc. 

 Beyond this zone there exists an elliptical interval, the 

 darkness of which is sometimes extremely marked. Then 

 begins a vague nebulosity, of a milky appearance, which 

 gradually becomes more distinct, becoming intensified up 

 to the vicinity of Enceladus, which limits, so to speak, 

 this second nebulous ring. After the fourth, this is the 

 faintest, the third being the brightest and the most fre- 

 quently visible. 



This third ring does not seem to pass beyond the orbit 

 of Tethys ; this satellite seems to graze the outer margin 

 ot the ring, and to round off its outline. 



Lastly, between Dione and Rhea, Dom Lamey 

 has observed the outer margin of a fourth ring, very faint 



