spectrum would reveal to us solid or liquid matter in the circumsolar regions; a spectrum continuous or not containing bright lines would give us gases or vapors; the ordinary solar spectrum, with its dark lines, would indicate matter incapable of radiation itself, and therefore cool, reflecting to us ordinary sunlight. It is clear that the problem would be complicated if circumsolar matter both reflected sun light and sent us its own; and still more so if we allow that the coronal light may be partly contributed from reflections and refractions in our own atmosphere. Then we have to consider whether the light thus contributed may possibly be due to the photosphere or to the prominences, and we are landed in a maze of difficulties which need not be discussed here.

The system of sketching introduced for this eclipse is at once so simple and final that the only wonder is that it has not been introduced before. The corona must be either solar, atmospheric, or subjective, that is, more or less built up in the observer's eye, this more or less depending cæteris paribus upon the brilliancy of the undoubted solar portion. If at all stations, the stations being as wide apart as they have been this time, the drawings are similar, then the corona would be undoubtedly cosmical; if dissimilar, then it would either be terrestrial or subjective; and this point could and would have been settled this time, if the weather had permitted, by arranging the observers in pairs, that is, dealing with two observers in each place instead of a single one, and so obtaining the eye-variations.

This being premised, what is the result of the very few observations, comparatively speaking, which have been made? Before I attempt to give any idea of my answer to this question, it is only fair to myself to state that my only sources of information, up to the present time, have been conversations with some of the American members of the Sicilian expedition, a brief telegram from the members of the English party at Agosta, the Rev. S. J. Perry's communication to the Daily News of the 2nd instant, and an inspection of some drawings made by the officers of H. M. ships off Aci Reale. At Catania we saw a portion of the corona for 14 seconds through a cloud, and that was all; and the day after the eclipse, before the more fortunate members of my party returned, it became my duty to proceed to Malta in H. M. S. Lord Warden to attend the court-martial on the officers and crew of the beautiful but unfortunate Psyche, in which we had been wrecked on the 15th ult., and the weather in the Mediterranean had been so bad that it was impossible to leave Malta in time to rejoin the expedition before they left for England. Of detailed information, therefore, I have none.

We

In the first place, then, I submit that the fact that the corona is a compound phenomenon comes out in an unmistakable way. have first of all a ring some 5' or 6' high round the moon, which almost all observers have seen alike; and then we have light beyond which some observers have seen of one shape and some of another, now stellate with many rays, now stellate with few, now absolutely at rest, now revolving rapidly.

This I think to be the key-note of all the observations with which I have become acquainted. I need scarcely say that it is exactly what had been predicted.

First among the fortunate ones who observed the corona with the telescope was Prof. Watson, of Ann Arbor, who took up his station at Carlentini, and appears to have been the best favored among the Sicilian observers. From his account I gather that there was an almost perfect shell around the sun about 5' high, and that outside this shell were less definite rays. What he was particularly struck with was this, that, as seen in the telescope, the rayed portion was most developed over the prominences, and as I gathered from him in one case, the rayed portion was absent as if a veil had been removed; so that he, at all events, is strongly impressed with the idea that the shell represented a true solar appendage, and that the rayed structure was due to our own atmosphere.

Next comes Mr. Brett, who, although he was not so fortunate, still was enabled to see and place on record some most interesting features, including the whole outline of the corona and even some of the protuberances. He also, as I am informed, saw the rayed portion of the corona most developed above the protuberances, the outline of the interior portion being visible, though not so strongly marked as in the case of Prof. Watson's drawing, in consequence of less favorable atmospheric conditions. I am thankful to say that the weather at Syracuse enabled Mr. Brothers to obtain some admirable photographs, which I have not yet seen. These are among the most important results of the expedition.

Next I must mention Prof. Peirce, the head of one of the American parties, who observed two miles north of Catania, at a private casino of the Marchese Sangiuliano. I believe that he also saw the shell, but of this I am not absolutely certain; but he distinctly observed that the outer corona over the prominences was rosy red, although he did not see the promicences himself. A more beautiful proof of the terrestrial nature of this portion of the corona it would be difficult to imagine: for, of course, at the sun, the hydrogen, which thus tinged it, is incapable of coloring anything, as its own light is absorbed by the transcendent brilliancy of the photosphere; while nothing would be more natural than to suppose that the light, which, in its own atmosphere, should strongly tinge anything radially illuminated, should be that of the prominences.

But the strongest proof of the variability of the outer portion and of the constancy of the inner portion is afforded by the observations made on board the small fleet attempting to save the Pysche off Aci Reale, where the eclipse was observed in unclouded splendor. Here were the ironclads Lord Warden, Caledonia and Royal Oak, and the tugs Weasel and Hearty, besides the Italian gunboat Plebiscito, all within a stone's throw of each other. In all the drawings, and many have been received, we have a ring 5' or thereabouts, while the outer portion is as variable as may be. On the same deck, that namely of the flag-ship, Lord Warden,

two drawings were made, one by Capt. Brandreth, and the other by Dr. Macdonald, F.R.S., in which the variation is so strong that one would feel inclined to acquit the atmosphere of any participation in the matter, and to relegate the whole outer corona to subjectivity alone, did not Mr. Brother's admirable photographs show both phenomena, as I am told they do. Dr. Macdonald saw eight rays arranged with perfect symmetry; Capt. Brandreth saw only two elliptical hoops crossing each other at right angles.

Capt. Cochran, of the Caledonia, besides the ring, saw a complicated stellate figure, the rays of nearly equal length, while Mr. Dexter, at sea between Catania and Syracuse, saw, besides the ring, only one ray of inordinate length.

So much for the drawings. I think that if the records of former eclipses be now examined, especially Mr. Carrington's drawing of the eclipse of 1851, and compared with the others taken at the same time, additional evidence will be gathered in favor of the compound nature of the corona, which on the evidence now before me, I consider the great teaching of the present eclipse. Our experience in Sicily seems to be similar to that of the Spanish observers, for Mr. Perry writes that, "some observed two curved rays," while the rapid degradation of light occurred at one-fifth of a solar diameter, but, so far as I know, no one in Sicily was favored with a view of the dark intervals which were observed in Spain.

There is a strange and most interesting discordance between some of the spectroscopic observations made in Sicily and Spain. At Agosta, where the totality was well visible for ten seconds, Mr. Burton detected a green line near E, with a tangential slit (distance from moon not stated). This line, which was also seen by the Italian observers, is doubtless the one recorded last year by the American astronomers, but in Spain Mr. Perry states that bright lines at C near D, b (or E) and F were observed 8 away from the sun. At Syracuse, Prof. Harkness, whose telescope was moved into the various positions by Capt. Tupman, R.M.A., found the green line in all parts of the corona, so far as about 10' from the sun, and at one point thought he detected two green lines, less refrangible than it; but at several places he saw a complete hydrogen spectrum (including C) which he attributed to prominences, until he was informed by Capt. Tupman that there was no prominence near the slit. More proofs of the terrestrial nature of this portion of the corona, I think, taken in connection with the fact that the dark moon gave identically the same spectrum. It would appear that there was so much atmospheric reflection in Spain, and here and there at Syracuse, that the true coronal spectrum with its line near E, the existence of which we must now accept as established beyond all question, was partially masked by the prominent spectrum with its usual well-known lines. There is one passage in Mr. Perry's interesting letter in which, if there be a misprint, as I suspect there is, an observation of great importance is recorded. It runs, "Mr. Abbay, observing at Xeres with a

spectroscope of 2 prisms of 45° belonging to Prof. Young, saw the bright lines, C, D, F; and afterwards F, and a line rather more bright than F on the less refrangible side of B, C not noticed then." Now, if b (not B) was intended here we have sub-incandescent dydrogen mixed with the green-line-giving-substance, which may probably be a new element with a vapor density less than hydrogen.

So that roughly we might regard the chromosphere to be built up of the following layers, which are in the orders of vapor density in the case of known elements :

The foregoing table excludes naturally the substance or substances which give bright lines in the solar spectrum, which are at times visible in the spectrum of the chromosphere. I have ventured to suggest that the substance which gives the line in the green is a new element, because invariably I have found that in solar storms the chromospheric layers are thrown up in the order of vapor density, and because all the heavier vapors are at or below the level of the photosphere itself.

With regard to the question of polarization, the parties in Sicily obtained evidence that the corona was radially polarized, though Profs. Harkness and Eastman obtained a result which they explain differently. Mr. Raynard, at Villamonda, and Mr. Peirce, Jr., north of Catania, obtained identical results in favor of strong polarization. Hence the solar corona, accepting these observations, not only radiates, but reflects solar light to us. A careful consideration of this fact, taken in connection with the possible addition of a, so to speak, terrestrial corona to its light, may enable us to account for some of the observations, both polariscopic and spectroscopic, which do not at first appear to harmonize with those to which I have referred, notably those which give a pure continuous spectrum to the corona, and which state that its light is only slightly polarized.

From what has preceded, then, we seem justified in suggesting as working hypotheses the following, which, however, more accurate information may alter, and which I offer as suggestions only, bien entendu.

(1.) The Solar Chromosphere extends some 5' or 6' from the sun (Watson and others), its last layers consisting of cool hydrogen (Mr. Abbay), and possibly a new element with a green line in its spectrum (Young, Burton, and others); which line, if it be identical with the auroral line as stated by Gould, may possibly be present in the higher regions of our own atmosphere.

(2.) Outside this stratum the rays, &c., are for the most part due

partly to our own atmosphere, partly to our eyes, for their shape varies; they are seen by some at rest, by others in motion, and their spectrum is the same as that of the dark moon (Maclear).

(3.) The white light of the chromosphere above the prominences, as seen in an eclipse, is due to its strong reflection of solar light, as shown by the polariscopic observations (Ranyard, Peirce, Jr., Ladd).

(4.) The rosy tinge of the corona proper, that is of the region more than 5 or 6' from the sun, is due to our atmosphere containing light which comes from both the higher and lower strata of the chromosphere (Peirce, Sen., Maclear, Abbay.)

2. Appendix to the Washington Observations of 1868.-The Superintendent of the U. S. Naval Observatory, Commodore SANDS, has published the Appendix I to the Washington Observations for 1868, being a catalogue of 1963 stars, and a catalogue of 290 double stars, reduced from observations made at Santiago, Chili, during the years 1850, 251, '52, by the U. S. N. Astr. Expedition, Captain Gilliss, Supdt., Lieut. McRae, Master Phelps, and Captain's Clerk, L. R. Smith, Ássistants.

The observations upon which these catalogues are based were intended to constitute vol. IV of the Report of the Expedition, but no appropriation has been made for their publication in full, though the manuscript is ready for the printer.

We heartily join Prof. Harkness in his introduction to the catalogues, in expressing the hope that it may yet be possible to procure sufficient funds to complete the reductions of the observations which were to constitute vol. V, the other unpublished volume of the report. These give the positions of 27,500 stars within 25° of the south pole. If the full observations could be published, it would be preferable. If not, a star catalogue deduced from them should be accessible to astronomers.

H. A. N.

3. Professor Young on the Eclipse.-The letter from Professor Young, of Dartmouth College, an abstract of which is published on page 156* of this volume, in a postscript to the February number, was addressed (as was not stated in the Tribune from which it was cited) to Dr. Henry Morton, President of the Stevens Technological Institute, Hoboken.

IV. MISCELLANEOUS SCIENTIFIC INTELLIGENCE.

1. On Spontaneous Generation; by E. FRANKLAND.-I have repeatedly subjected various solutions for Dr. Bastian to a temperature of 150° to 156° C. in sealed vacuous tubes, in order that he might afterward submit them to a microscopical search for living organisms. The result of this search led him to conclude. that living organisms had been generated from non-organized matter, whilst Professor Huxley, who examined the contents of one of the tubes, considered that no such conclusion could be drawn from his own observations. I therefore determined to repeat these experiments, operating in exactly the same manner as before in the preparation of the solutions, the sealing them up in vacuous tubes, and exposing them to a high temperature, but taking additional and much more stringent precautions against the subsequent admission of atmospheric germs into the tubes.