spectively exhibit a mean of about 44°. On examination, I perceive that this analogy might be extended further.

The gale at NE, with which this frost came in, brought with it abundance of snow, which loaded the trees to their tops, and weighed down the smaller shrubs to the ground. The peculiar clinging quality of some snows merits inquiry. It is in part the result of the needly crystallized texture, aided by a degree of moisture attending, which afterwards freezes in the mass; but as light volcanic ashes have been found likewise to possess this quality, and in a still higher degree, perhaps we ought to attribute something to the electric charge with which each of these light bodies arrives at the earth. The seasonable covering which snow affords to the vegetable kingdom is matter of common remark; but it is not so generally understood in how great a degree the very circumstance of its production abates the first rigour of the cold. Just before this snow the air was extremely moist; the snow cleared it of an inch and a half, nearly, of water, and it has since indicated considerable dryness. Now it is quite probable that the vapour which afforded this water was found, by the supervening NE current, diffused in our local atmosphere, and by it decomposed. In this case the latent or constituent heat given out by the vapour in passing to the solid state, must have gone in great part to raise the temperature of that current. Hence a considerable interval, of gradually increasing cold, before we experienced its extreme effects; during which, too, the earth got provided with its accustomed covering.

After a copious fall of snow, an observer may find, in the scenery which it forms, some things on which to exercise his powers of reflection. The pensile drifts, which in a mountainous country are objects of just alarm, may be contemplated, here, to discover the principles of their construction, and the manner in which they rest on so narrow a base. When the sun shines clear, and the temperature is at the same time too low for it to produce any moisture, the level surface may be found sprinkled with small polished plates of ice, which refract the light in colours as varied and as brilliant as those of the drops of dew. At such times, there are also to be found on the borders of frozen pools, and on small bodies which happen to be fixed in the ice and project from the surface, groups of feathery crystals, of considerable size, and of an extremely curious and delicate structure. From the moment almost that snow alights on the ground, it begins to undergo certain changes, which commonly end in a more solid crystallization than that which it had originally. A notable proportion evaporates again, and this at temperatures far below the freezing point. On the night of the 10th of the second month I exposed 1000 grains of light snow, spread on a dish (which had previously the

temperature of the air), of about six inches diameter. In the first hour after dark it lost five grains; in the second, four grains; in the third it acquired a grain, the wind having changed, and the temperature, which had been falling from 25°, inclining to rise again. The hygrometer was at 50°, with a gentle breeze at east. In the course of the night the loss was about 60 grains. This evaporation from snow may very well supply the water for forming those thin mists, which appear in intense frost: and the slight increase during a part of the time, in this experiment, may throw light on the formation of the secondary icy crystallizations above-mentioned. It appears that the air in a still frosty night becomes partially loaded, either with spicula of ice, or with particles of water, at a temperature below freezing, and ready to become solid the moment they find a support. Hence the rime on trees, which is found to accumulate chiefly on the windward side of the twigs and branches.

As to those more copious mists, of the modification Stratus, which accompany the setting in of long frosts, I conceive them to originate in part from the yet unfrozen rivers, and other waters, near which they are most abundant; in part from the moisture of the earth itself: for it is contrary to experience to suppose, that the frozen state of the surface can prevent the ascent of vapour from the porous soil below: which will continue to emit it, until its temperature becomes, by the gradual penetration of the frost, nearly on a level with that of the cold air then constantly flowing over it, though too gently to disperse the cloud formed.

The snow on the Grampian Hills, in Scotland, is at this time of a greater depth than has been known for the last 20 years. Vast flocks of grouse have come down from them for shelter.-(PUB. LEDGER, February 23.)

EARTHQUAKES FELT AT SEA.

Extract of a letter from Madeira, dated February 5.-" On the 1st instant, about 12 o'clock at night, a severe shock of an earthquake was felt all over the island; and the following morning, at four o'clock, another shock was felt."

The shock of an earthquake, which we lately stated, was experienced at Lisbon, about one in the morning of the 2d February, was repeated rather more slightly at seven. The first is supposed to have lasted from two and a half to three minutes, and was generally and regularly felt in the whole city.

February 27.—A few days since the Ann transport, A. Clarke, master, arrived at Portsmouth, from Antigua. On the 2d February at 45 minutes past 11 a. m. being a little to the southward of the latitude of Lisbon, and about 150 miles to the eastward of St. Mary's (one of the Western Islands), she experienced the shock of an earthquake. The spot precisely was long. 19° 30' W,

lat. 37° 30' N. The sensation produced was what would have been felt had the ship touched the ground, or her motion been impeded by a strong counterundulating current; the masts trembled, as they would preceding their fall over the ship's side. The ship was thrown aback, with the sails; and the lead being thrown, with 150 fathoms of line, no ground was touched. At twenty after three o'clock, on the same day, she experienced another shock, which produced the same sensations, but in a much less degree; the ship was then in long. 17° 4′ W, lat. 39° N ; the lead was again thrown, and no bottom could be found with 200 fathoms of line. After this period, until three o'clock on the following morning, the 3d instant, several other similar convulsions were felt-but every successive one producing a less effect: the whole number of shocks was 12.

Extract of a letter from Captain Welsh, of the Claudine, arrived in the Downs from Batavia.-" On the 9th of February, off St. Michael's, we experienced very tempestuous weather, with a tremendous confused sea. The wind shifting from SW to SE and NE, with constant lightning and heavy rain. On the 10th, at half-past 8 p. m. the ship then under reefed fore-sail and mainstay-sail, we were much alarmed by a severe shock of an earthquake, which lasted four or five seconds.-(PUB, LEDGER.)

NOTES. Second Mo. 20. Light clouds. 21. Several birds sing: Cirrostratus beneath large Cirrus. 22. Cloudy drizzling: fair: windy. 23. White frost, which speedily went off: there appears to have been a dripping mist in the night: Cirrocumulus: fair. 24. Cirrus: Cirrostratus: cloudy: hollow wind. 25. A gale from SW, with showers: changed to NW in the night. 27. A snow shower early, which was followed by sleet and rain: much wind in the night. 28. Light Cirrostratus, a. m.: windy: Cumulus and Cumulostratus succeeded. 29. Slight hoar frost: fair, with light clouds: hygrometer went to 42°.

Third Mo. 2, 3. Rain at intervals. 4. Cirri, a. m. consisting of streamers rising from a horizontal base, with Cirrostratus below: heavy clouds: wind: p. m. hail, sleet, rain: lastly, upon the wind getting somewhat northerly, a heavy short storm of snow. 5. Clear

a. m.: the ground crusted with yesterday's snow. 6. Various modifications of cloud, a. m.: heavy showers, p. m. 7. Cloudy: some rain,' a. m.: Nimbi. 8. Rainy. 9. Snow storm: much evaporation : fair night. 10. Fair. 11. Stormy: very wet, p. m. 12. Temperature 50° at 9 a. m.: wind and rain. 13. Much wind: rain at intervals: Nimbi. 14. Wet morning: the wind SE: stormy day and night. 15. Much wind: rain, p. m.: calm at night. 16. Hoar frost: fair: calm hygrometer went to 45°; and although it was overcast through the day, with the usual indications of rain in the sky, yet none fell. 17. Cirrus, with other light clouds, a. m.: wet, p. m. 18. Wet morning: hollow southerly wind, which changed to NW, with Nimbi at night, and blew strong. 19. A raw blustering day, with much evaporation evident.

Character of the period: cloudy, wet, and windy: vegetation has made but little progress.

EARTHQUAKE.

On Sunday, March 17, about half-past twelve o'clock, a violent concussion of the earth was sensibly felt at Doncaster, and at Bawtry, Blyth, Carlton, Worksop, Sheffield, Chesterfield, Mansfield, Nottingham, Lincoln, Gainsborough, &c.-(DONCASTER PAPER.)

On Sunday a smart shock of an earthquake was perceptibly felt in Lincoln, at about ten minutes before one o'clock in the day. The undulation appeared to be from west to east, and lasted from about a minute and a half to two minutes. The wind was at the time SE, cold, and with every appearance of rain. Pictures and other articles hanging on the walls were set in a swinging motion. At Newark, also, and the neighbouring villages, the shock was distinctly felt, as well as at Leicester and Loughborough.-(STAMFORD PAPER.)