At 6h. 51m. M. T., twenty-five minutes after contact, on a large prominence, C lengthened to half height of spectrum; nine minutes afterwards cusp was at another prominence; the positions of these must have been about N. 13°, and nearly north.

At 7h. 8m. M.T. I watched with the direct vision radial, and, besides the hydrogen and "near D" lines, observed another bright line a little more refrangible than the air band between b and F. At 1830 Kirchhoff it was very faint, and soon disappeared; soon after this I saw F line double about the same height as usual, oneeighth spectrum.

At 7h. 23m. M. T., having returned to the 6-prism radial to the cusp, I observed the hydrogen D, E and b very plain; several lines then began to come into view, as near as I could judge all the iron lines from halfway between D and E to beyond b. These kept on brightening and more lines coming in. I called Mr. Lockyer to look at the phenomenon, and we watched it together for two or three minutes until it became time to take position to observe totality. During these two or three minutes the cusp must have passed from about N. 38° E. to N. 70° E. or farther, and the lines were not lost sight of till I moved the telescope and placed the slit tangential to the point where the light would disappear, keeping it there with R.A. movement. On looking through the spectroscope the field was full of bright lines, the light just enough to let me distinguish the positions from the well-known solar lines.

D

As totality came on the light decreased, and the lines increased exceedingly rapidly in number and brightness, until it seemed as if every line in the solar spectrum was reversed; then they vanished, not instantly, but so quickly that I could not make out the order of their going, except that the hydrogen D, b, and some others between Ď and b, remained last. Then they vanished, and all was darkness. I then unclamped, and swept out right and left, but saw nothing; then went to the direct vision, but saw nothing; placed the telescope on the moon's limb by the eye-piece, then put in the spectroscope, but the light was not sufficient to show any spectrum; pointed the telescope carefully, first on the dark moon, and then on a bright part of the corona, but no spectrum. I then looked at the corona with the naked eye, saw a bright glory around the moon, stellar form, six-pointed, something like the nimbus painted round a saint's head, extending to a diameter and a half. Looked through the finder, and saw the same form, but very much reduced in size and brilliancy; then examined with the 6in. and eye-piece, and saw nothing but a bright glow round the moon, not much more than the height of the big prominence plainly visible in the S.E. quarter. The last thirty seconds had now arrived, and, as previously arranged, Mr. Lockyer took my place at the 6in., while I again looked through the 6-prism spectroscope to record anything that might be visible, but I saw nothing. As the spectroscope was not on the sun's limb at the re-appearance of the light, I cannot state what took place.

During the remainder of the partial eclipse I watched the north ern cusp as the moon uncovered the sun, and several times I saw

distinctly the four bright lines near C; but saw nothing else worth recording.

*

The color of the corona appeared to me a light pinkish white, very brilliant. I saw no streamers. The rest of the sky and everything around had a bluish tinge. * *--Nature, Jan. 18. 3. The Solar Eclipse of Dec. 12. Observations made at Poodocottah; by L. RESPIGHI.-The spectral observations of recent total eclipses of the sun had plainly demonstrated the existence of an incandescent gaseous stratum or atmosphere, surmounting the chromosphere or stratum of hydrogen which envelops the body of the sun, but they had not sufficed to determine its true conformation and extent. This question, therefore, constituted one of the principal problems remaining to be solved by observations of the eclipse of the 12th of December, 1871.

The slit-spectroscope applied to large telescopes doubtless affords the best means of verifying the existence, in the circumsolar regions, of this gaseous stratum, which may be termed the superior chromosphere, and of determining the materials of which it is composed; but from the shortness of the time available in an eclipse, the spectroscope can furnish only partial and local results, insufficient, therefore, to reveal the true structure, form, and dimensions of this upper chromosphere.

Preceding observations having shown that the light of the solar corona is composed for the most part of a small number of elementary rays differing considerably in refrangibility, it appeared to me that the form and dimensions of the higher chromosphere might be much more conveniently studied by means of a large prism fixed in front of the object-glass of the telescope, whereby the several chromatic images of the corona would be distinctly formed in the focal plane. If the prism has but little dispersive power, and the eye-piece does not magnify too much, all the chromatic images of the corona may in this manner be observed simultaneously in the same field, and their form and dimensions directly investigated.

Towards the end of the year 1868, a small flint-glass prism was made for me by Signor Merz, of Monaco, to be fitted to the objectglass of the equatorial belonging to the Observatory of Campodoglio, for observations on the spectra of the stars; and this apparatus, in consequence of the dispersion of the prism, and the goodness of this prism and of the object-glass, was found to be admirably adapted for observing the eclipse in the manner just described.

The dispersion of the prism from the lines C to H of Fraunhofer is about 32'; the free aperture of the object-glass is 43 French inches; the field of the telescope is about 1°, with a magnifying power of 40.

My conviction of the great advantages which would be afforded by this instrument in the observation of the approaching eclipse, induced me to carry it to India for that purpose; and I was glad to learn that Mr. Lockyer, the chief of the expedition, had in like manner resolved to observe the corona by means of a spectroscope without a slit, being persuaded that this would be the most con

venient method of solving the questions relating to the corona itself. With this instrument, then, I prepared to observe the eclipse, proposing to myself the following problems:

1. To ascertain whether, just before the beginning, and at the end of totality, the solar spectral lines are reversed-a phenomenon observed by Prof. Young in the eclipse of 1870.

2. Amidst the several chromatic images of the prominences, to observe especially whether the image given by the yellow line D, coincides with that of the lines of hydrogen gas.

3. To define the form and dimensions of the chromatic images of the corona. * **

To verify the phenomenon of the reversal of the spectral lines at the extreme edge of the sun, I had arranged the plane of dispersion at right angles to the edge at the point of second contact.

At thirty seconds before totality, the spectral image of the luminous crescent was already sufficiently weakened to allow of its observation by the naked eye without a dark glass; and it was then that the principal dark lines of the solar spectrum came out distinct, and even more strongly marked than before, and curved parallel to the bright edge of the sun; but a few seconds before totality these lines disappeared completely, and the spectrum became continuous, without however exhibiting, just before totality, the reversal of the lines, although I was watching most intently for this phenomenon. I would not, however, be understood as denying altogether the reversal of the lines, for it is not impossible that a thin film of mist, or the bright atmospheric light at that time diffused over the spectrum of the solar limb, may have concealed the bright lines.

At the very instant of totality, the field of the telescope exhibited a most astonishing spectacle. The chromosphere at the edge, which was the last to be eclipsed-surmounted for a space of about 50° by two groups of prominences, one on the right, the other on the left, of the point of contact-was reproduced in the four spectral lines, C, D3, F and G, with extraordinary intensity of light and the most surprising contrast of the brightest colors, so that the four spectral images could be directly compared and their minutest differences easily made out.

In consequence of the achromatism of the object-glass, all these images were well defined, and projected in certain colored zones, with the tints of the chromatic images of the corona. My attention was mainly directed to the comparison of the forms of the prominences on the four spectral lines; and I was able to determine that the fundamental form, the skeleton or trunk, and the principal branches, were faithfully reproduced or indicated in the images, their extent being, however, greatest in the red, and diminishing successively in the other colors down to the line G, on which the trunk alone was reproduced. In none of the prominences thus compared was I able to distinguish, in the yellow image D3, parts or branches not contained in the red image C.

Meanwhile the colored zones of the corona became continually more strongly marked, one in the red corresponding with the line C, another in the green, probably coinciding with the line

1474 of Kirchhoff's scale, and a third in the blue, perhaps coinciding with F.

The green zone surrounding the disc of the moon was the brightest, the most uniform, and the best defined. The red zone was also very distinct and well defined, while the blue zone was faint and indistinct. The green zone was well defined at the summit, though less bright than at the base; its form was sensibly circular and its height about 6' or 7'. The red zone exhibited the same form and approximately the same height as the green, but its light was weaker and less uniform. The height of the green zone was estimated by comparison with the moon's diameter, and from the observed distance of the spectral lines of the prominences.

These colored zones shone out upon a faintly illuminated ground, without any marked trace of color. If the corona contained rays of any other kind, their intensity must have been so feeble that they were merged in the general illumination of the field.

Soon after the middle of the total eclipse, there appeared on the eastern limb, at about 110° from the north point, a fine group of prominences formed of jets rather low but very bright, some rectilinear, others curved round the sun's limb, and exhibiting the intricate deviations and all the characters of prominences in the neighborhood of solar spots. The brightness and color of these jets were so vivid as to give them the appearance of fire-works.

The spaces between some of these jets were perfectly dark, so that the red zone of the corona appeared to be entirely wanting there. Perhaps, however, this was only an effect of contrast due to the extraordinary brightness of the neighboring jets. I have thought it right to refer to this peculiarity, because the appearance of interstices, or dark spaces, between prominences of considerable brightness, is often observed by means of the spectroscope, independently of total eclipses.

The want of an assistant to note the time, and to write down the observations as they were made, occasioned me some loss of time, and the end of the total eclipse was already at hand before I was aware of it.

The green and red zones were well developed at the western as at the eastern limb, while the blue remained faint and ill-defined. Soon after the appearance of the chromosphere at the western edge, there was suddenly projected on the spectrum of the sun's limb, which then appeared beyond that of the moon, a stratum of bright lines, separated by dark spaces; but I could not determine whether they were due to a general or partial reversal of the spectral solar lines, or to a simple discontinuity in the spectrum, since they were too soon immersed in a flood of light, which put an end to the totality of the eclipse. * *-Nature, Jan. 25. 4. Prof. Young on the results of the Eclipse observations.-In an article in the Boston Journal of Chemistry, Prof. Young thus speaks of the results of the observations on the recent solar eclipse, in establishing his interesting discovery in 1870, of the reversal of the Fraunhofer lines in a stratum close to the sun:

*

"The reversal of the Fraunhofer lines seems to have been satisfactorily observed by Captain Maclear at Bekul, Colonel Tennant

at Dodabetta, and Captain Fyers at Jaffna. It was partially seen by Pringle at Bekul, and Respighi at Poodocottah, and probably by Pogson at Avenashi. How it was with Janssen I do not know. His instrument, however, on account of the small size of the sun's image, was not very well adapted for this observation.

Mosely, at Trincomalee, did not see it. Mr. Lockyer missed it by an accidental derangement of the telescope. He says further, 'At the last contact Mr. Pringle watched for it and saw no lines.' How the mistake occurred I do not understand, but Mr. Pringle's own words are, 'At the end of totality a considerable number of lines flashed in; what proportion of the whole I cannot say, perhaps one-third.'

Captain Maclear writes, 'As totality came on the light decreased, and the lines increased exceedingly rapidly in number and brightness, until it seemed as if every line in the solar spectrum was reversed; then they vanished, not instantly, but so rapidly that I could not make out the order of their going.'

This description applies exactly to what I saw in 1870, except that the lines then made their appearance more suddenly-they flashed out like the stars from a rocket head; but the discrepancy is easily enough accounted for by supposing that the portion of the sun's limb last covered by the moon was then more quiet than at the time of Captain Maclear's observations."

IV. MISCELLANEOUS SCIENTIFIC INTELLIGENCE.

1. Correspondence relating to the Dismissal of the late Botanist to the Department of Agriculture. Reprinted from the American Naturalist for January, 1872. 8 pages, 8vo. In the pages of the Naturalist, and in this pamphlet, this case has been so far made known that we can well enough refer to it without reprinting the correspondence, although this indeed is not long. That the botanists of the country should have felt aggrieved by the treatment accorded to one of their number is natural, and some expression of their indignation might not have been out of place. But in the published correspondence they have confined themselves first. to a respectful request to the Commissioner of Agriculture that he "would take into consideration the propriety of re-appointing Dr. Parry to the position of Botanist in the Department of Agricul ture;" then, on receiving an unfavorable reply, to which the Commissioner gratuitously appended the intimation that were it not for his desire to spare Dr. Parry in the estimation of his friends, he could say something to Dr. Parry's disparagement, one of their number claimed to be informed as to the nature of the delinquency insinuated, and was accordingly "put in possession of the whole subject," in a reply from the Commissioner, and thereupon (permission asked and granted), the correspondence is printed, that it may speak for itself. Leaving the case to make its own impression upon the Commissioner's own showing, no comment was made beyond the following preface.

"Dr. Parry was thought to have performed the duties of Botanist to the Department of Agriculture to the entire satisfaction of