number of NATURE as having been seen by Mr. Denning at Bristol on the evening of the 23rd ult., as well as a single other shooting star noted during a watch of the sky whenever it was clear by the same observer on that evening, seem, from their apparent courses, to have been both possibly directed from the now well-known radiant point of the meteors of Biela's comet, but only a small number of shooting stars appears to have been visible on that night. During a watch for ten minutes, kept at four different times between half-past 7 and half-past 9 P. M. on the following evening, near Regent's Park, in London, Mr. H. W. Jackon observed, in each watch, a shooting star as bright as a first-magnitude star directed in each case from the recently determined radiant point; while, with an equally uncloudy sky, on the following evening of the 25th, three small meteors from the same radiant point, and two brighter ones from other directions, were seen by Mr. Denning at Bristol between 8 and II P.M. in two intervals of a watch for half an hour. A small meteor of the same stream was recorded by Mr. Denning on the 26th, but their numbers on this, as on the previous nights, were evidently inconsiderable, a clear view of the sky on the night of the 26th, between 11h. 20m. and 12h. 40m., affording Mr. Jackson, at Tooting, no observation of a single meteor. The time of first approach and commencement of the bright star-shower seen on the evening of the 27th ult. must therefore have been later than shortly before I o'clock on the previous morning. A completely overcast state of the sky after midnight on the night of the shower appears to have prevented observations of its close, and probably of its complete extinction on that night, after the greatlydiminished intensity which it had then attained; but a correspondent in London informs me that, in spite of the densely overcast state of the sky, which prevented any view of the shower from being obtained in the metropolis, an ceedingly bright meteor was seen to flash like lightning through the clouds at about 4 o'clock, A.M., 28th. On the evening of the 28th Mr. Greg watched for shooting stars, and for any remnants of the star-shower of the previous evening which might be visible, at Buntingford, in Herts; but although the sky was quite clear he failed to see any meteors. A strict watch for outlying meteors of the shower was also kept by two observers at Hawkhurst, in Kent, on the evening of the 28th, where the sky was quite cloudless between 9h. and 11h 15m. P.M., but without success, only four shooting stars of ordinary character being visible during more than two hours of their simultaneous watch. An interval of about fortyfour hours is thus clearly determined in which the first indications of the star-shower must have arisen, reaching the maximum of its intensity towards the middle of the period, and disappearing so completely before its termination as to leave the whole expanse of the sky almost as perfectly free from shooting stars as it was before its commencement.

ex

on the

In addition to the early appearance of the shower recorded in NATURE of the 5th inst. as having been seen near Dublin, I have received the following communications from observers relating to its early visibility and abundance. At Brancepeth, near Durham, Mr. Joseph Lawson first began to count the meteors at 5 o'clock, and continued to enumerate them until, towards 7 o'clock, their constantly increasing frequency obliged him to desist. During the last half hour of his estimation the rate of their appearance was about ten per minute, while a total number of 1,000 meteors was counted between 5 and 7 o'clock. The rate of their appearance in the first was thus little less than that of their appearance in the latter portion of his watch. Mr. S. J. Miller, at Wisbeach, first noticed the abundance of shooting stars at 5h. 40m., and counted in three minutes twenty meteors, or about six or seven per minute. Soon after this, at about 6 o'clock, their number was ten or twelve per minute. During their appearance before 6 o'clock, Mr. Wood, at Birmingham, considered them to be falling from 5h. 45m. when he first observed them, at a rate of about fifteen per minute, while the result of his enumeration between 6h. and 7h. was at least 600 meteors, and in occasional intervals between 6h. and 7h. 15m., when the sky became gradually overcast, the average rate of appearance was found to be increasing nearly uniformly from 8 to 10 per minute, showing that the intensity of the display before 6 o'clock was little inferior to the maximum which it appears afterwards to have gradually attained. At York the first attempt to estimate their numbers was made by Mr. T. H. Waller, at 5.30 o'clock, when the meteors were found to be appearing at the rate of 12 or 15 per minute. At 6 o'clock their numbers had increased to about

20, and at 7 o'clock to about 30 or 40 per minute for one observer. At 8 o'clock the best determination of their numbers was however obtained by two of Mr. Waller's scholars, who, standing back to back, counted 79 meteors in Im. 15s. or 31 meteors per minute for each observer. The principal maxima of the shower at about 6h. 30m., and Sh. 15m. P.M., as mostly clearly shown by the continuous observations of Mr. Lowe at Highfield House, and by Prof. Grant, who was assisted in his observations at the Glasgow Observatory by Prof. G. Forbes, are also generally indicated by the observations which I have received, and the gradual diminution of the shower after 9 o'clock was observed at Newcastle-upon-Tyne as well as by some of the observers who combined in their watch for its appearance for the British Association. The frequency of the meteors after 9 o'clock was regarded by Mr. Wood as not more than a quarter of what it was at about 6 o'clock, when they were first seen, yet these numbers continued for some time to be considerable and quite unusual. Near Rothbury, in Northumber land, repeated estimations of their abundance were made by Mr. G. A. Lebour in different parts of the sky, and at different times between the hours of 7 and 10 o'clock, with the following results :--

From 7h 20 to 7h 28m 100 meteors falling perpendicularly in the west (the east cloudy). 100 meteors falling vertically in the east (the west cloudy).

7 35 7 45

7 40 7 48 9 15

100

9

10 0

Meteors too numerous to count at 9h., falling in showers at 9h. 15m, especially in the north; one bright red with beautiful red streak, which lasted more than 10 seconds. Meteors still falling, but in smaller numbers.

In 20 minutes after 10 o'clock 35 meteors were seen by one observer in a clear part of the sky, which scarcely exceeded a quarter of the sky. In 10 minutes after II o'clock ten meteors only were counted in the same space, and in 20 minutes after 12 o'clock 9 meteors only could be seen. The rate of decrease of the shower from shortly before 10 o'clock until after midnight was thus apparently more rapid, and the decline of its intensity appears to have been considerably more complete than the first brightness and progress of its gradual increase may be concluded to have been during the earliest hours of its observation. Newcastle-upon-Tyne, Dec. 7 A. S. HERSCHEL

The De Novo Production of Living Things WILL you allow me to ask Dr. Bistian to state in your columns, in reply to this note, the specific gravity of the turn ip infusion, to which a "fragment" of cheese has been added, and which, he states, has rarely failed to give him positive results in his endeavours to obtain evidence of the de novo production of living things from dead matter. If Dr. Bastian should be un able to give the specific gravity of the infusion, perhaps he will be so good as to state accurately the weights of water, turnip, and cheese employed. I am, of course, acquainted with the directions he has already given, but wish to avoid any objection from him or others on the score of improper preparation of the infusion to results which I may obtain and publish. E. RAY LANKESTER

Exeter College, Oxford, Dec. 7

The Birth of Chemistry

YOUR correspondent, "A. H.," in alluding to my mention of the Insula Cassiterides, inquires whether the name was derived from a Sanskrit source. The word karrírepos is used both by Homer and Hesiod, and it is possible that it may have been borrowed from the Sanskrit kastira, and that tin was first procured from India. The Sanskrit word for tin-kastira-is clearly related to the verb kas, to shine. It is strange that the Arabic word for tin is kasdir, closely resembling the Sanskrit, although there is no family relationship between the languages. Possibly the Phoenicians first procured tin from India, and gave it a name resembling its native name kastira; then the Greeks converted the Phoenician word into Karoírepos, the Romans borrowed the word from the Greeks, and the fact of the scarce

metal being found in certain islands north of Spain was suficient to secure for them the distinctive title of Insula Casiterit, or¦ Tin Islands. G. F. RODWELL

The Greenwich Date

UNDER this heading, in your number for Nov. 28, a letter signed "James Pearson" ends thus :-"The query then is in what part of the globe and in what meridian does October 20 end and October 21 begin?" As well ask where a circle ends and where it begins. See an article at the end of Bayle's Dictionary, entitled, in the second Rotterdam edition, 1702," Dissertation sur le jour," vol. iii. p. 3118; in the London edition, 1741, "Dissertation concerning the Space of Time called Day," vol. x. p. 365. The difficulty, as Bayle shows, is in the nature of things. Let an equatorial railroad go round the world in twentyfour hours, with a station at every 45th meridian. At noon of October 20, Mr. West takes "a return ticket" westward; Mr. East takes one eastward. Both reckon by solar time. At every station Mr. West finds it noon, and on his return home reckons noon October 20; but the station-master reckons noon October 21. Mr. East at 45° sees the sun set at 6 o'clock. At 90° he finds midnight; at 135° the sun rises at 6 o'clock on October 21; at 180° it is noon. Here the two passengers pass each other, Mr. West reckoning it to be noon of October 25, Mr. East noon of October 21. At 135° W., Mr. East sees the sun set at 90° he finds midnight; at 45° the sun rises at 6 o'clock on October On his return home Mr. East reckons it to be noon of October 22. Here then are three different reckonings, and practically the keeping of Sunday, Christmas Day, &c., on different days in different countries exists at this instant and must exist for ever. Practically also those who sail eastward round the world get one more dinner than those who stay at home. Those who sail westward round the world get one dinner less than those who stay at home, and two dinners less than those who sail eastward, when both voyages are completed.

22.

MR. PEARSON'S query, in NATURE of November 28, does not admit of any exact or scientific answer, for there is no natural line of demarcation or change, and the settlement is entirely a matter of usage or convenience. It is not very many years since the dates at Manilla and Macao were different; and till the cession of the Alaska Territory to the Americans, the date there was different from that in the British Territory adjoining. The rule now generally held is, that places in E. long, date as if they were arrived at by the Cape of Good Hope, and places in W. long as if they were reached via Cape Horn-a rule that the width of the Pacific renders practically convenient. Afloat, the rule is for a ship making a passage to change her date on crossing the meridian of 180°, or as soon after as the captain may find convenient ; repeating or omitting a day, according to the direction in which she is going; but a ship merely cruising across the meridian, with the intention of returning, does not generally change her date, so that ships having different dates may and do occasionally meet—a very marked instance of which occurred during the Russian war, when our squadron from the Pacific joined the China squadron on the coast of Kamschatka.

And thus, according to established usage, October 21 at Adelaide, and October 21 at the hypothetical place in 9h. 35m. W. long., are different days; in the two places October 21 has a different meaning. J. K. LAUGHTON

Royal Naval College, Dec. 1

THE Rev. J. Pearson is correct in the method of finding the corresponding Greenwich date, although its numerical performance is incorrectly performed in his letter.

It is absolutely necessary for practical purposes to draw the line somewhere, and it is drawn in England an her colonies as well as in America and Russia, at the meridian 180° E. of Greenwich. The limit, therefore, of the longitude to be added to or subtracted from the Greenwich date will not exceed twelve

hours.

It is usual for sailors, when crossing this meridian, to skip a day, or to reckon the same day over again, according as the

meridian has been reached from the eastward or westward.

An instance of this apparent anomaly is furnished in the Appendix to the "Nautical Almanac" for 1874. The time of the phenomenon of the transit of Venus over the sun's disc takes place generally about December 8, 16h. Greenwich astronomical time. Its recorded local astronomical time for the middle of the transit at Auckland, New Zealand (long. 174° 42′ E.), is December 9, 3h. 40m. ; but for Woahoo (long. 158 W.) the time of the first contact of Venus with the sun's limb takes place at December 8, 3h. 4'7m. Blackheath Road, Greenwich, Dec. 2

Comets' Tails

EDWARD ROBERTS

CAN any of your readers refer me to a work by a recognised authority in astronomy in which I can find the method by which the direction of a comet's tail, as regards that of the heliocentric radius-vector of the head, has been calculated from observation? Or, more briefly, have we any proof whatever that there is other than an occasional chance coincidence of these two directions? G. H.

REMARKS ON THE ZOOLOGY OF THE FAROE ISLANDS

AS SI have already announced in this paper, I started with the Danish expedition in September from Copenhagen, and arrived after a very fortunate voyage of four days in Torshavn, the little capital of Faroe in the isle of Strömö. There I intended to remain while our steamer, with the geologists and engineers, went to the southern island (Sudero), where the miocene coal deposits are to be seen some hundred feet above the level of the sea in the basaltic rocks near the village of Qualbö. As to their researches about the extension of the coal-fields in Suderö, directed by Prof. Johnstrup, and as to the possibility of taking the coals over to Copenhagen at a reasonable price, I cannot say anything now, as the report must first be made to the Minister of the Interior, who will perhaps afterwards publish the results. Some words, however, about my own zoological researches in Torshavn will, I think, have some interest for the readers of NATURE.

I remarked in my preceding paper that no wild mammals were known to occur in the islands, except some species of the genus Mus. This is, as I now know, not quite correct; for some thirty or forty years ago the northern hare (Lepus alpinus) was introduced into the islands, and it seems to have met with very favourable conditions of life, as it is now spread in considerable Oesterö. The hare finds ample food in the grasses covernumbers over Strömö, and has also been brought to ing the ground; the large rocks spread everywhere protect him, and no mammals or birds of prey endanger his life, with the exception of Corvus corax, or the little Falco aesalon, which sometimes might take the younger ones. The occurrence of the Falco islandicus is too rare to do any serious damage to the hares. Besides these, they have also endeavoured to introduce the "ripers" (Tetrao lagopus) so common in Iceland and Norway, but those set free have perished without breeding. These birds require food and protection from trees, which, as it is known, do not occur in these islands.

The rats found in the northern islands of Faroe (although they have not yet come to all the islands) belong to the species Mus decumanus, which here, as nearly everywhere in Europe, has nearly destroyed the smaller black rat (Mus rattus), still, however, to be found in some houses of Suderö. In the "fields" still another

species of rat is said to occur, not heretofore seen by naturalists. Mr. Randrop of Torshavn, who has taken great trouble in order to secure a specimen of the animal, the footsteps of which he has seen, thinks it is the Lemmus norvegicus, but he could never get it. Among the large aquatic mammals the "Grindehval" (Delphinus globiceps) is known to be of great importance here, as nearly every year large flocks of it are taken, which they drive to the

shore by boats, and the flesh of which is divided after old northern laws still in use in this country. Some hundreds of this whale had just been killed in Westmannshavn (west side of Strömö) some days before we arrived, and I still could examine pieces of the animals brought to Torshavn. I immediately looked after external parasites, but would not have got them if Sysselmand Müller, the wellknown magistrate and naturalist of Torshavn, had not had the kindness to give me some specimens. These are two species of Cirripedia, one of them being an Otion, which often attaches itself to the teeth of the dolphin, where it easily finds food; as the surface water, coming in, is full of little creatures (infusoria, crustacea, &c.), which the Otion catches by aid of its arms. Another very interesting external parasite of the dolphin is the Xenobalanus globicipitis Steenstr., which Sysselmand Müller has discovered in large numbers on the fins of the whale. An allied species, also described by Steenstrup, is found on the fins of Uranodon rostratus, a whale met with in small flocks of four and five, especially near the southern island, where one of them was killed during the stay of the expedition. In Torshavn I also sought to get the intestines of the grindehval; but these, of course, had already been thrown into the sea, with the exception of the stomach, in which I have found the rests of Cephalopods, the usual food of this whale, and the common Ascaris.

At the time when we arrived in Faroe the celebrated "Fuglebjergs" (bird-rocks) were unfortunately already deserted by their inhabitants, so that I have seen nothing of their extraordinary life. Of one of them Sysselmand Müller has taken up excellent photographic views (Trollhovedet, near Sandö), which give a very good idea of them, and deserved to be published in an ornithological work. We see in it clearly the different stages which the birds occupy in the rocks, the highest of them being the sea-parrot (Mormon fratercula), then a Larus, and undermost Uria. Only the little Thalassidroma pelagica was said to be still breeding (September), and I therefore resolved to see the nests. In the rocks of the northeastern side of Naalsö these little birds breed in a depth of one or two feet, their nest being simply a hole in the earth. One of the natives lifted the stones for me, then bent his ears to the holes, and, when he heard the birds piping, broke them up. In this manner we took an egg containing an embryo, with the old bird, which did not even endeavour to run or fly away, and three younger ones in different stages of growth. The Thalassidromæ have only one egg, but they seem to breed twice or thrice a year. In the neighbourhood of this place, they told me, the nests of Procellaria glacialis were also to be found. Besides these, the birds usually met with were Authus campestris, Saxicola ananthe, Motacilla alba, Troglodytes parvulus, Tringa variabilis and islandica, Numenius phaopus, and Hamatopus ostralegus, Carbo, Sterna, Larus, &c. We also got some living specimens of Sula alba, only occurring in the island of Myggenaes, and of Lestris cataractes, now not very common in Faroe, for the Zoological Garden in Copenhagen. Occasionally they have also taken the Pastor roseus and once Syrrhaptes paradoxus. The former bird is known to appear sometimes in Norway and Heligoland (nearly every summer)-a very remarkable fact, as these birds, which are known to breed in Southern Russia and Asia Minor, have so very seldom been met with in Denmark or in the interior of Germany.

Fishes are caught abundantly on the shores of Faroe; so that, for example, the klippfish trade is very considerable. The Gadus are opened, spread out and dried on the rocks (klipps), and are exported to Spain and France, their swim-bladders being used for the fabrication of gelatine, and their ovaries being prepared for the use of the anchovy fishers in the Mediterranean. Of remarkable fishes only the Lampris guttatus Brünu was taken during

my stay in Faroe, inhabiting the great depths of the Atlantic, and coming only by accident to the shores of these islands. This was the third specimen taken there, an enormous creature, weighing 76 Danish pounds, having a length of 99 centimetres, and a breadth of 52. The colour was a magnificent silver blue with red spots; it had been taken by the fishers in the King's Harbour (Kongshavn), and was admired, when brought to Torshavn, by large crowds of people who had never seen it. Before dissecting it, Sysselmand Müller took a photograph,

which has been reproduced in the accompanying woodcut. We then separated the principal muscles from the bones (the flesh looked like salmon's, but its taste was not quite so good), in order to get the skeleton, and I dissected the intestines. In the stomach I found the same remains of Cephalopods, which also Kröyer mentions (in " Danmarks Fiske") in the specimens he examined. Of the internal parasites I may here only mention an agimic Ascaris in the outer walls of the stomach, and a cestoid in the intestinum tenue. External parasites were eagerly sought for, but not found.

Very interesting to me were the lakes in the interior of the islands, as I hoped to get there something like those animals ("relicts") found in the lakes of Sweden and North America. I accordingly dredged in one of them, but did not find anything of importance. I also examined the three species of Salmonide of these lakes, one of them being the Salmo salvelinus, known to to be found in the lakes of Upper Bavaria and of Scotland. More about these inhabitants of the Faroe lakes may shortly be seen from a paper which I am to publish in v. Siebold and Kölliker's Zeitschrift; and the same periodical will also contain the results of my investigations on the Annelids from the shores of Faroe, which formed the principal object of my researches. I may here only remark that, on the whole the invertebrate fauna of the shores of Faroe, as well as of Iceland, is very poor compared with that of Greenland, Norway, or Denmark; so that the place is not to be recommended to those who wish to get in an easy manner favourable objects for anatomical or embryological observations. When I was there the currents were sometimes so strong that, even with the heavy oyster-dredges of Jutland, we did not reach farther down than 15 or 20 fathoms. And as to the surface-fauna, it was, with the exception of some few days, quite impossible to do anything, as the sea was too much agitated. In midsummer, of course, all those obstacles will vanish. Nevertheless, I could every day get fresh materials, as when the sea was rough I was sitting on the rocks of the shore, and selecting the animals from the sand and sea-weeds brought up in the harbour of Torshavn by my fisher, Zacharias Hansen, a very brave man, whom I recommend to every naturalist coming to Faroe in the future. With respect to comfort, my stay in the island was very agreeable, thanks to the care which Mr. and Mrs. Hansen were always good enough to take of me.

RUD. V. WILLEMOES-SUHM

automatic spectroscope having the dispersive power of 13 prisms. The instrument was loaned for the occasion by the trustees of the College, who, for the good of science, have never hesitated to send their most valuable apparatus to any portion of the earth; and thus far, I am happy to say, have met with no loss in so doing.

Our observatories, one for the transit instrument, one for the meteorological apparatus, and one for the equatorial, were "shanties" of rough boards, placed upon the summit of a slight elevation, some 150 yards S. E. of the railway station, and some 40 or 50 ft. above the track. The altitude of the observatory was about 8,300 ft. above the sea; the approximate latitude was 44° 7'; the longitude about 1h. 53'2m. west of Washington, or 7h. 14m. west of Greenwich. I give only approximations, the accurate reduction of the observations being not yet completed.

To the east the horizon was bounded by hills of no great apparent e'evation, nor was there anything in the general aspect of the nearer landscape to remind the careless observer of his altitude. To the north, at a distance of about three miles, but seeming not more than half a mile away, rose some picturesque piles of granite several hundreds of feet in height; to the north-west lay the socalled Laramie hills; and from the north-west to the south, across the broad green Laramie plains, toward the mountains, many of them capped with perpetual snow. In the south were Long's and Gray's peaks, some 60 miles away; nearly west lay somewhat nearer the great mass of Medicine Bow; and between them, over the lower ridges, rose some of the high mountains of the Colorado parks. None of these snow-capped peaks have an elevation of less than 13,000 ft., and several exceed 14,000.

Our principal object was to ascertain what advantage would accrue to astronomical, and especially to spectroscropic, work, by placing the instrument at a great elevation. Theory declares that the gain ought to be great, since it is certain that our atmosphere, by its continual currents, its impurities, and its reflective power, is a most serious hindrance to telescopic work, and at the height of 8,000 ft.-more than a fourth of the whole is left below. The experiment of Prof. Piazzi Smyth, in 1856, on the Peak of Teneriffe, had already given a practical demonstration of the fact, so far as relates to ordinary telescopic work; but that was before the day of spectroscopy.

Although, on account of unfavourable weather, the amount of work accomplished was to some extent diminished, the results obtained were of considerable interest and value.

In the first place, the geographical co-ordinates of the station were completely determined; so that henceforth it will be a reference point and base for all the numerous surveys, geological and others, which are going on in that part of the country.

Then a complete hourly meteorological record was obtained for nearly the whole of the months of June, July, and August, a record which, from the exceptional character of the station, on the very back-bone of the continent, must possess the highest value, unless the fact that the season was also an exceptional one should prevent us from applying confidently to other years the conclusions it would indicate.

If we may credit the residents of the country, especially an old trapper who had lived among the mountains for nearly twenty years, the amount of cloudy and rainy weather during the summer was most unusual. Deducting a single week, during which every night and the greater part of every day was fine, clear nights were very rare, and clear days only a little less so. Indeed during our whole stay there were but two afternoons during which work upon the sun could be kept up uninterruptedly from noon to sunset, though during the same time there were more than twenty mornings.

Undoubtedly the explanation of this state of things is

to be found in the enormous quantity of snow which fell last winter, and was still, in the middle of July, lying 8 ft. deep on the plateau at the base of the Medicine Bow

mount.

Whenever the sky was unclouded the air was usually of most exquisite transparency. At night multitudes of stars, invisible at lower elevations, were easily seen; so that it was estimated that nearly all the stars of the seventh magnitude were fairly within reach of the naked eye. For instance, in the quadrilateral which forms the bowl of the "Dipper" I could see distinctly nine stars, with glimpses of one or two more, while at home I can only perceive the three brightest of them.

The power of the telescope was correspondingly increased. Without being able to devote a great deal of time to stellar observation, I ascertained that, with my 9t inches of aperture, nearly everything could be fairly seen which, at the sea-level, is within the reach of a 12-inch object-glass.

Some most exquisite views of Saturn will always be remembered, in which, notwithstanding the planet's nearness to the horizon, the inner satellites, and the details and markings of the rings, especially a dark stripe upon the outer ring, about a third of its width from the outer edge, were clearly shown under powers ranging from 500 to 1,200.

But in the use of the spectroscope the advantage was even greater. At Hanover I had been able to make out a list of 103 bright lines in the spectrum of the chromosphere; at Sherman the number was extended to 273; and at moments of unusual solar disturbance there were glimpses of at least as many more.

Sulphur, strontium, and cerium are pretty conclusively shown to be constituents of the solar atmosphere. Zinc, erbium, didymium, and iridium are also indicated, but not so certainly.

At the very base of the chromosphere, and to a distance of perhaps 1" or 15" from the edge of the photosphere, it was found that those dark lines which are not actually reversed lose their intensity, and vanish more or less completely. This is substantially a confirmation of an old and somewhat disputed observation of Secchi's, who reports at the edge of the sun a layer giving a continuous spectrum.

This is not strictly correct, however, since when the transparency of the air is so much increased as to cause the most persistent of the dark lines to vanish, a multitude of the others appear reversed. There can be little doubt that were the effect of our own atmosphere entirely removed, this lowest portion of the solar atmosphere would give the same spectrum of bright lines which is seen at the beginning and end of totality during an eclipse.

It is noteworthy that of the 170 new lines found in the chromosphere spectrum, not a single one lies below C, and that for no want of careful examination. The only new lines of much importance are the two Hs at the extreme violet end of the spectrum. These were found almost constantly reversed, probably quite so, but the observation was so difficult that we could not be perfectly sure of it on every occasion.

What is still more remarkable, it was found that these two lines (not the hydrogen lines, as has been erroneously reported) are also usually, and I am pretty confident always, reversed in the spectrum of sun-spots, not so clearly, moreover, in the nucleus as in the penumbra, and over a somewhat extensive region surrounding it. This reversal of the H lines does not involve at all the disappearance of the dark shade, but a bright streak rather than a line makes its appearance in the centre of the shade, which itself is, if anything, a little intensified.

The spectra of several different spots were carefully studied, and a catalogue was drawn up of 155 lines which are more or less affected, usually by being greatly widened, but in some cases by a weakening or reversal. Several