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broken stream of aëriform matter, are also formed by the operation of the controlling mechanical cause to which, acting in the second place, the entire system of phenomena presented by the spots is here attributed. These torrents are continuously maintained from near the surface of origin on the glowing sphere within to that of the photosphere without, whether in single or in groups of separate and probably often confluent streams, elevating the photosphere into faculæ by the force of expansion with which they burst upon it, and, being transparent, permitting the interior envelopes and the incandescent nucleus to be seen through them.

The observed spherical form of the sun is considered to be preserved by the perpetual escape from its equatorial regions, by means of the ebullition of the spots, of matter which, in consequence of the sun's rotation, would otherwise accumulate upon them, and so cause a deviation, from the spherical form. Being thus separated, it receives from the sun's rotary motion at the equator the form of the Zodiacal Light, which it thus constitutes, while the perpetual supply of fresh matter from the solar surface causes it to be, not a ring, but a lenticular mass, geometrically though not physically continuous with the originating central body, which it thus envelopes, no interval apparently being left between them.

The next objects of discussion are the "Origin of Meteorites, Series of Physical Processes of which they are the result, and their Functions in Nature."

The vapours of metallic and other elementary matter evolved or discharged in the ebullition of the photosphere above considered, partly remain upon the sun, constituting its atmospheres,* but are principally aggregated into masses of immense magnitude (terrestrially speaking), of the nature of bubbles, which, having undergone a certain amount of condensation, first become visible as those particles the collective brightness of which reveals to us the existence of the zodiacal light, being, in fact, the matter separated from the sun's equator, as explained above. These particles, termed by the author meteoritic masses, are projected from the zodiacal light by the force to which its variable extension is owing, and are further gradually condensed during their passage

* Companion to the Almanac for 1864, p. 46; for 1865, p. 53.

through the interplanetary spaces into the liquid and solid state, constituting eventually the nuclei of meteors, which are finally precipitated upon the earth (and doubtless upon the other planets) in the form of METEORITES.

The sudden outburst of light over a solar spot witnessed on September 1, 1859, by Mr. Carrington and Mr. Hodgson, the author regards as a fact confirmatory of these views, and as having been the consequence or accompaniment of the production, and the transfer with immense rapidity from within to without some exterior region of the sun, of a meteoritic mass, or more probably of an immense congeries of such masses, enabled, by its consisting of ponderable matter, to manifest the higher temperature and consequent greater effulgence of the interior regions of the luminary whence it was originally derived. Certain phenomena, before recorded by astronomers but not yet understood, are probably of the same nature.

The succeeding section of the paper is headed, " Original Formation of the Planets; Origin of the Primitive Heat of the Earth; Causes of its Permanence and Invariability; the Earth not a Cooling Body." In this it is represented that the results of modern science conspire to prove that we must look to causes now in operation as those which have produced the planets. If-as first evinced by Mr. G. Poulett Scrope, with respect chiefly to volcanic and plutonic action; and secondly, but from wider induction, by Sir C. Lyell -they are sufficient to account for the phenomena of its surface and crust, as made known by geology, it follows, by parity of reasoning, that they will be sufficient to account also for its original production. The only known phenomenon in which the process of the formation of the earth as a planet is actually observed, is that of the fall of meteorites upon it, by which its magnitude is augmented, and that by the addition of materials homogeneous with those of its existing elementary constitution, being chiefly those chemical elements which are present in the greatest quantity in the earth's crust, and seem to be most essential to its constitution. The characteristic presence of iron in both has been already adverted to. According to the adequacy of existing causes, therefore, we must conclude that the fall of meteorites is a continuation or a residue of the process of formation of our

204 Inferences in Cosmical and Geological Philosophy.

planet, and that the earth was originally produced by the aggregation and coalescence of meteorites, or of greater masses into which they had previously coalesced.

Admitting the earth to have been formed as here suggested, such also must have been the process of formation of the other planets.

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A "Discrimination of these views in Cosmical Philosophy from those of Mayer and his School" is here interposed. According to the physicists of the Mayerian school, the activities of nature begin with the mutual attraction of "Cosmical masses,' of which meteorites are taken as examples.* In the theory now offered they commence with Force and Heat, and Light and Matter, locally originating in the sun.

The "Theory of the Minor Planets" is next briefly considered. All the phenomena they present are regarded as supporting the conclusion that their peculiar relations and community of character are not, as hitherto supposed, effects of their having formerly constituted one heavenly body which has been reduced to fragments, but of their being bodies intrinsically of the same nature, meteoritic masses in fact, in an advanced intermediate state between the condition of meteorites and that of true planets, in process of gradual convergence towards each other, preparatory to their coalescence into one greater planet.

The last section relates to the " Projectile Power of the Sun," accounted for in the section on the spots, and by which meteoritic masses are conceived to be transferred with great velocity to the interplanetary spaces.

Everything here ascribed to the sun is, of course, intended to apply in a general manner to the stars also, as far as our knowledge of them extends; agreeably to the primary cosmical truth that they are suns, "which must be characterised, each in its own system, by the uniqueness and peculiarity which characterise our sun in its system."†

No suggestion is offered in this paper as to the remote origin of the solar elements, or that of the force by which they are conceived to be condensed into ponderable matter.

* Companion to the Almanac for 1865, pp. 41-70.

+ Syllabus of Lectures on Astronomical Physics. Lecture VII.

CORRESPONDENCE.

N.B.-We do not hold ourselves answerable for any opinions expressed by our correspondents.

02 CYGNI.

TO THE EDITOR OF THE ASTRONOMICAL REGISTER. Sir,-In reply to Mr. Williams's enquiries in the June number of the Register relative to the group O2 Cygni, I beg to offer the following remarks. By a slight oversight, or by a misprint, Struve's coordinates for the star D are incorrectly quoted in the cycle. On turning to the Mensura Micrometricæ I find the following results: Pos. 323° 41'9, Dist. 337833, Epoch 1835'95, which would seem to suggest that in Admiral Smyth's observed angle there is also a misprint of 333°8 for 323°.8. This correction would bring all the measures into admirable accordance. The group forms a beautiful object in the telescope, from the finely contrasted colours of its components.

Those of your readers who are interested in coloured stars will find a fine red, or ruddy orange star, 2m. 438. following 12 Aquilæ, and about 25 further north. It is No. 1442, Hora xviii., of Weisse's Catalogue, and its approximate mean place for 18650 is R.A. 18h. 57m. IIS. Decl. S. 5° 53'0. When I first 'swept it up' in October 1861, its colour struck me as a very fine crimson. I have latterly fancied it not quite so deep in tint, and am rather inclined to suspect that it is slightly variable. It is of about the 7.3 magnitude.

I take the opportunity of submitting the results of recent measures of several interesting stars, taken with my 73-inch Alvan Clark refractor, and a Filar Micrometer. With the exception of the distances of Cancri, and of μ Herculis B.C., the results depend on at least two nights' measures.

Pos.

Dist.

Epoch.

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The measures of y Virginis were all taken by daylight. The distance will be seen to be o" 204 in excess of that given by Mr. Fletcher in the July number of the Register, and is, perhaps, rather too large. I am, Sir, yours faithfully, GEORGE KNOTT. Woodcroft Observatory, Cuckfield:

July 14th, 1865.

P.S.-I fear I must have spoken rather carelessly at the R.A.S. meeting in June, judging from the report in the Register for July. I cannot, from my own experience, say anything as to the variability of the small companion of Cygni. The Baron Dembowski's ground

for suspecting it variable, 'soit en couleur, soit en grandeur,' rests on the fact that while in 1862 he had often observed the star by day, in 1863 he had only succeeded in doing so on one occasion, and that with some difficulty. My observation of & Cygni on the evening of the 8th June was made with a power of 610 (not 110) on my 7-inch equatorial. The colour of the small star, which I estimate as Blue3 of Admiral Smyth's chromatic scale, is very fine.

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