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NOMENCLATURE OF CLOUDS.

THAT general readers may not be embarrassed by the technical terms of the clouds, in their perusal of the daily remarks on the weather, &c. (under the meteorological tables) in which frequent mention is made of them, with a view to point out the particular changes which the lower medium is undergoing from its alternate dryness, humidity, and electric state, as caused by the combined influence, and attractive forces of the sun and moon over the incumbent atmosphere; we shall here insert, as a general reference, concise definitions of the respective modifications of clouds, which were first invented by Luke Howard, Esq. and published in the Philosophical Magazine, and which have been coming into general use among meteorologists ever since they were published monthly in the meteorological tables in Gold's London Magazine. They are as follow:

1. Cirrus. A cloud resembling a lock of hair, or a feather. Parallel flexuous, or diverging fibres, unlimited in the direction of their increase.

2. Cumulus. A cloud which increases from above, in dense, convex, or conical heaps.

3. Stratus. An extended, continuous, level sheet of cloud, increasing from beneath.

These three, Mr. Howard denominates simple and distinct modifications, constituting, as will immediately appear, the elements of every other variety. The two next are of what he calls an intermediate

nature.

4. Cirro-cumulus. A connected system of small roundish clouds, placed in close order, or contact.

5. Cirro-stratus. A horizontal slightly inclined sheet, attenuated at its circumference, concave downwards, or undulated; groups or patches having these characters.

Lastly, says Mr. Howard, there are two modifications, which exhibit a compound structure, viz.

6. Cumulo-stratus. A cloud in which the structure of the Cumulus is mixed with that of the Cirro-stratus, or Cirrocumulus. The Cumulus flattened at top, and overhanging its base.

7. Nimbus. A dense cloud, spreading out into a crown of Cirrus, and passing beneath into a shower. In addition to these definitions, the following is an abridgment of the illustrations, from Howard's Essay on the Modifications of Clouds. The Cirrus is always the least dense, and generally the most elevated modification, sometimes covering the whole face of the sky with a thin transparent veil, and at other times, forming itself into distinct groups of parallel lines, or flexuous fibres. Its height, according to Mr. Dalton, is

from three to five miles above the earth's surface. It is generally found to be an indication of wind. When formed into horizontal sheets, with streamers pointing upwards, it indicates approaching rain; with depending fringe-like fibres, it is found to precede fair weather.

The Cumulus is generally of dense structure, appearing after a clear morning, increasing from above, where its surface is convex, and forming at its greatest magnitude, a pile of irregular semicircular clouds. This takes place about the time of the greatest heat of the day, and gradually diminishes towards evening, when it sometimes perceptibly evaporates—in this case it is an indication of fine weather.

The Stratus is of moderate density, and comprehends those creeping mists which rise from the valleys and lakes in calm evenings. It frequently disappears in the morning, and is then an indication of the finest weather.

The Cirro-cumulus appears to be formed by the descent of the Cirrus, the oblique denser tufts of the latter changing into the spheroidal form, when the cloud assumes the appearance of a ball of flax with one end left flying out. The Cirro-cumulus sometimes consists of distinct beds, floating at different altitudes, the clouds appearing smaller and smaller, till they are lost in the blue expanse. It is most frequent in summer, and, when permanent, affords one of the surest indications of an increasing temperature, and fine weather.

The Cirro-stratus assumes various appearances, from its being frequently connected with other modifications. By itself it is always an attenuated sheet or patch, of an uniform hazy appearance, when viewed over head, and of great apparent density towards the horizon. In this state, it gives rise to the phenomena of halos, mock-suns, &c. and indicates a depression of temperature, wind and rain. When it alternates with Cirro-cumulus, the prognostic is doubtful. It is frequently seen resting on the summit of high hills; and, in this state, has been long regarded as foreboding rainy weather.

The Cumulo-stratus is that fleecy cloud which is sometimes observed to settle on the summit of a Cumulus, while the latter is increasing from beneath. It usually prevails in an overcast sky, and apparently without any regard to temperature, as it is found to precede either a fall of snow, or a thunder-storm. Before a storm, it is frequently to be seen in different points of the horizon, rapidly swelling to a great magnitude. Its indication is doubtful, and must be determined by the prevalence of the other modifications that accompany it.

The Nimbus generally appears in the

form of a dense inverted cone of cloud, the upper part of which spreads in one continued sheet of Cirrus to a great distance from where the shower is falling. When the total evaporation of the cloud takes place after the shower, it is reckoned a prognostic of fair weather. When the Nimbus appears by itself, it generally

335 moves with the wind; but when formed in in a contrary direction. the midst of Cumuli, it sometimes moves This is often the

case with thunder showers.

upon the subject, may consult, besides the Those who wish for further information work already referred to, Dr. Forster's Treatise on Atmospheric Phenomena.

OBSERVATIONS ON THE WEATHER,
FOR JULY, 1821.

GENERAL REPORT.

The greatest part of this month has been fine, but cold for the season, particularly the first eight days and nights; in one of the latter a hoar-frost occurred without the town. To the heavy rain from the eastward on the 2d instant (being upwards of an inch in depth), and the subsequent NE. and NW. winds, that depression of temperature near the ground may be justly attributed. During 23 days of the month, not th of an inch of rain fell; but in the other 8 days and nights, upwards of 34 inches fell in this neighbourhood, mostly in the first and last quarters of the moon.

Last month the wind prevailed 14 days from the NE., and this month it has blown 10 days from the opposite point of the compass, generally in brisk gales.

The mean temperature of the air is more than 2o lower than the mean for July, in 1818, 1819, 1820, and 1821; but rather higher than the average heat of July, 1816 and 1817, yet the thermometer in the shade has not risen higher than 76° this summer: therefore, it is not probable that the sickle or the scythe will be put in general use in the low and level corn-fields before September.

The atmospheric and meteoric phenomena that have come within our observation this month, are 5 solar halos, 18 meteors, 2 of them caudated, lightning, with distant thunder, in the evening of the 19th; and 9 gales of wind, or days on which they have prevailed, namely, 1 from E. 1 from SE. I from S. and 6 from SW.-Also,

A Singular Meteoric Phenomenon.— A meteoric appearance of triangular and

Naval Academy, Gosport.

spheroidal forms was observed here on the 4th instant, between 9 and 10 o'clock, p. m. about W. by S. 11° or 12° above the horizon, and to the north of the moon, only to show small portions of her deep red which was hid by a cumulostratus, so as of that compound cloud. These geometric crescent at intervals through the apertures forms which it alternately assumed, and which were serrated about the edges, the diverging pencil rays that issued therefrom, both in horizontal and perpendicular direc tions; the surprising contractions and exwards of 14 to a mere point, and then pansions it repeatedly underwent from upgradually increasing to its former brilliancy and extent, were occurrences that led us to determine it was not a paraselene, though not much beyond the ordinary distance of in that part of the haze which was of a one from the Moon, but an electrical light cirrostrative quality. the above-mentioned cloud, advancing About 10 o'clock and gradually obscured this interesting slowly by a freshening breeze, came up, phenomenon, which had been conspicuous in a variety of forms and colours more than that saw it. Some attributed it to the half an hour, to the gratification of many Moon distorted, on account of its deep red greatly diffused comet-whilst others, of a colour and curious forms, and some to a duced by some uncommon light in the haze more liberal opinion, thought it was pronear the horizon, it having once or twice thrown out vivid corruscations not unlike those of the aurora borealis.

DAILY REMARKS.

July 1. Cloudy with cumuli and low attenuated cirrostratus, and a moist air: rain by night.

2. Heavy rain throughout the day and night, with a strong gale from the E.

3. Overcast, and a cold NE. breeze: a fine night, and a slight hoar-frost in the grass-fields.

4. AM. fair with cumuli: PM. plumose cirri and waved cumulostratus at intervals, through which the crescent of the moon appeared of a fiery colour.

day, and low haze: an overcast sky by
5. Broken cumulostratus nearly all
night.

6. AM. overcast: PM. light showers of

rain.

shrouded sky: linear cirri and nimbiform
7. AM. a cold northerly wind, and a
the afternoon; afterwards the sky became
clouds, with sunshine about two hours in
overcast again.

8. Fair, with various modifications of
clouds: a light shower of rain in the night.
2 B 2

9. Fair, with an increasing temperature, and a light breeze from NW., from which quarter nimbiferous clouds came about noon overcast after sunset.

10. Faint sunshine through an overcast sky in the morning: fair in the afternoon, and attenuated cirrostratus about the sky at night, with a light fall of dew.

11. Fair, with a whitish mist around the horizon, which, towards noon, transformed into nascent cumuli: PM. fine, with light airs, and cirrocumuli in beds.

12. The day nearly as the preceding, with the addition of descending cirri, which, towards sunset, passed to attenuated cirrostratus, in which there was a trace of a solar halo a fine night. At a quarter past nine PM. a light red meteor of a large size, and of a spheroid shape, appeared in its course from the zenith towards the north: its path, which was 35° in length, formed an angle with the horizon of about 60°, and a retardation was observed in its motion just before it disappeared.

13. Fair, with light airs from the eastward. A stratus of considerable density rose from the fields and lakes in a linear form in the evening, and soon formed into thick horizontal cirrostrati.

14. A fair day in the evening a large nimbus passed over, and let fall a light shower: : a fine night.

15. Heavy rain and wind in the day: the night as the preceding.

16. A fair day, with brisk variable winds: cloudless by night, and much dew. This is the first day this summer on which the maximum temperature of the air in the shade has been 760, or summer heat.

17. As the preceding day and night, excepting a decrease in temperature.

18. Fair, with nascent cumuli, and extensive beds of plumose cirri; the former were formed by the rarefaction of a low mist in the morning; and the latter passed to cirrostrati; at sunset, after being tinged with a very deep red by the horizontal rays of the sun. A fine night.

19. Fair, with a light gale from SE., and from the westward beds of cirrus, which, at mid-day, passed to attenuated cirrostratus, and produced a fine solar halo, whose radius was 2240. In the afternoon bright and dark cumuli and cirrocumuli, which passed to thunder-clouds, and let fall a light shower of rain at six PM. A strong gale from SW. through the night, and frequent flashes of red lightning, and distant thunder from the clouds to the N. and NE. 20. Fair, with a stiff breeze from SW.: a light shower of rain in the night.

21. The day nearly as the preceeding. Two brilliant meteors appeared between nine and ten PM.-one inclined to the eastward nearly in the direction of the wind, the other was opposed to it, and passed between the star Arcturus and the first in the

northern crown-at this time loose patches of cirrostratus were observed in different parts of the sky, succeeded by heavy rain and wind in the night.

22. Fair, with plumose and ramified cirri, also cirrocumuli, and low cumuli ; the latter, gradually evaporated after sunset, and a copious dew followed. Two small lofty meteors appeared to the eastward at eleven PM.

23. As the preceding nearly, but the wind much stronger.

24. A fine morning, and a faint solar halo: a shrouded sky in the afternoon, followed by a change of wind to the south, whence a very strong gale sprung up with rain.

25. AM. large nimbi and showers of rain: PM. a strong gale from SW. and low scud passed with the wind to NE., followed by rain.

26. Fine, with a mixture of clouds, and a gale from SW. with a velocity of about seventy miles per hour, as repeatedly ascertained by watching the well-defined shadows of the lofty cumulus clouds pass, in a given time, in the direction of the wind on level ground, from one object to another, whose distance was previously known.

27. As the preceding nearly, but calm after noon. From a quarter before till a quarter past 11 PM. four meteors appeared-the lowest and largest of these, at five minutes before 11 o'clock, descended in a southerly direction immediately under the constellation Bootes: both the head and train were red, the latter about 15° long, accompanied by a hissing, like a sky-rocket in its ascension, and did not disappear till a second of time after the complete extinction of the former-the sky at the same time was filling with cirrostratus, and soon became overcast.

28. AM. a stratus under a shrouded sky, and a solar halo: PM. opposite winds for some time, succeeded by an inosculation of cumuli with cirrostrati, and light rain. At half-past 10 PM. a small meteor passed under Dubhe in Ursa Major, and left a white train behind it about two seconds after the body had disappeared. From that time till 12 o'clock, eight other small meteors, nearly of the same height, appeared without trains, viz. two under the northern crown, and one on each side of it, one over Jupiter and Saturn, one near the Pleiades, and two in the brightest part of the milky-way to the southward.

29. AM. sunshine and dense clouds increasing: overcast in the afternoon; and rain, and a gale from SW. after sunset.

30. Rain, and a light gale from the same quarter in the day: overcast at night.

31. A veil of attenuated cirrostratus, whose base frequently appeared below the summit of the adjacent hills, shrouded the sky throughout the day and night.

METER.

3

10

11

12

13

14

16

18

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29 76 29-75 29-755 60 50 55 29 88 29-73 29-805 60 44 52 30-18 307 30-125| 67 49 58 30-22 30-17 30-195 69 53 61 30-05 29-89 29-970 66 50 58 D29-93 29-86 29-895 || 62 46 54

Med.

30-10 30-03 30-065|| 6549 57
30-16 301430-150 71 53 62
30-18 30 16 30-170 73 47 60
30-18 30-12 30-150 68 53 60.5
30-08 3008 30-080 69 50 59
30-03 29-95 29-990 68 52 60
29-88 29-86 29-870 74 54 64

1529-82 29-76 29-790 64 52 58

30-13 30-01 30-070|| 69 51 60
30-34 30 27 30-305 76 52 64
30-34 30-24 30-290 70 57 63.5
30-10 29-97 30-035 75 60 67.5
29-93 29-88 29-905 || 75 58 66.5
29-85 29-83 29-840 74 58 66
29-64 29-62 29-630 72 54 63
29-72 29-64 29 680 71 58 64.5
29-80 29-62 29-710 71 60 65 5

29-91 29-69 29-800 70 57 63.5
30-02 29-92 29 970 70 56 63
30-07 30-0130 04071 54 62.5
29-98 29 94 29-960 || 69 50 59-5
30-10 30-08 30-090 || 72 57 64:5

Kept at the Observatory of the Naval Academy, Gosport.

The units under "Clouds" represent the days on which each modification of cloud has appeared.

Phases of the Moon.

BAROMETER. THERMO

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At 8 AM.

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SW
SW

30 32

251 01

31

39

15

|30-34 29-6229-966 || 76 | 44 | 61.52|| 59-5 51.264.1

[212828 427|18|14|2 903-65

The observations in each line of this Table, under Barometer, Thermometer, Wind, and Rain, are for a period of 24 hours, beginning at 8 AM.

RESULTS.

Maximum...... 30-34 July 17th, Wind North-West.
BAROMETER
Minimum.... 29.62 Do. 22d, Do. South-West.
0.72
Range of the Mercury
Mean barometrical pressure for the Month

for the lunar period, ending the 28th instant...
for 15 days, with the Moon in North declination
for 14 days, with the Moon in South declination
Spaces described by the oscillations of the Mercury
Greatest variation in 24 hours..

29.966

29-960

29-867

30-053

4.760

0.380

27.

769 July 17th Wind W.
44 Do. 3d Do. NE.
32
61.52
60.13

Number of Changes, caused by the variations in the Weight of the Atmosphere.....

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26:00 52.08

DE LUC'S WHALEBONE HYGROMETER.

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........ 100° in the evenings of the 30th and 31st. ........................................ 35 several times ....... 65

-- of 3 observations each day at 8, 2, and 8 o'clock

Evaporation for the month

Rain and hail, for Ditto

Prevailing Winds, SW.

59.5

64-1

.... 58.3

2.90 inches. ..... 365 ditto.

A SUMMARY OF THE WEATHER.

A clear sky, 2; fair, with various modifications of cloud, 16; an overcast sky, without rain, 6; rain 7-Total, 31 days.

CLOUDS.

Cirrus, Cirrocumulus, Cirrostratus, Stratus, Cumulus, Cumulostratus, Nimbus.

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COMMERCIAL REPORT. (London, Aug. 21.)

NOTHING having occurred within the last month, tending materially to affect our foreign trade, we shall not have occasion for any particular remarks, beyond those which are better placed under the respective heads. The great question of peace or war in the east of Europe still remains undecided; yet it seems probable, that peace will be preserved by the influence of England, France, and Austria, whose own interest naturally leads them to avert a contest, in which, if the event should be successful, Russia must be the chief and perhaps the only gainer.

Cotton. On a review of the four last weeks, it appears that the market has been on the whole in an improving state. In the two weeks ending August 7, the demand for Surats, in particular, was brisk and extensive, the sales being about 6,300 bags, of which 4,800 were Surats. The buyers seem to have been chiefly speculators, induced to purchase on account of the unfavourable intelligence from the United States, respecting the crops of cotton, which are stated to have suffered much from inundations, so that the supplies will be much less than have been calculated upon. In the second week of August, the purchases were not extensive, being only 1,200 bags, but the prices were fully supported.

The inquiry has rather revived; the demand appears principally for exportation; the sales for the week ending yesterday are 1,600 bags, but it is probable, that the renewed inquiries will lead to extensive purchases during the week: the holders are very firm, and appear confident of realizing higher prices than the present market currency. The particulars of the 1,600 bags sold, are as follows: viz. in bond, 300 Pernams, 12 d. a 12d.; 420 Surats, 6d. a 64d. very ordinary; a few very good, 8d.; 160 Madras, 64d. good fair; 780 Bengals, 54d. a 51d. fair; good, 6d. and a few very good, 63d.; 100 Boweds, 94d. a 94d.; 62 Sea Islands fair, 16d.; and duty paid; 40 prime Demeraras, 13d.; 70 Berbice good fair 114d.; 18 Paras fair, 104d.; 50 Minas Novas good, 114d.; 33 ditto Geras good, 10d. and 15 ditto ordinary, 9d.; 8 Cariacous, 104d, a 11d.

At Liverpool, the market has been rather dull for these three weeks past; and prices have, on the whole, declined. The arrivals in the four weeks ending August 18, were 52,677 bags; the sales in the same period, 30,800 bags.

Sugar.In the last week of July, the public market was uninteresting; inferior browns were very low, but good qualities were scarce, and maintained their prices, but though few sales were reported, the delivery of 4,400 hogsheads of Muscovades

from the warehouses, indicated that extensive sales had been made privately, probably at low prices; the particulars of which did not transpire. The show of new sugars being extensive in the first week of August attracted buyers, and considerable purchases were made. The demand for good and fine sugars has since been considerable, and the prices fully supported, but the inferior descriptions exceedingly heavy. The refined market has been in a very depressed state, in consequence of the unfavourable accounts from the Continental markets: and a considerable decline has taken place. Very little has been doing in foreign sugars. The quantity of refined sugar exported in the first six months of 1821, was in value, 1,328,0291. of which, for about 544,780%. to Hamburg; 432,000l. to the Mediterranean; 235,000l. to the Baltic; 40,000%. to Ireland; 37,000l. to Bremen, &c.

The report for the week ending to-day (21st) is as follows:

The demand for good and fine Muscovades has continued steady; and for these descriptions, very full prices were realized; the soft brown sugars are in plentiful supply, and might be purchased at very low rates.

There are no new supplies of sugar at market this forenoon, owing to the coopers at the West-India warehouses having struck work, demanding a higher rate of wages; the supply at market, is, however, more than adequate to the demand. Muscovades may be stated very heavy at the previous prices; the sales to-day do not exceed 1,000 hogsheads. Two public sales of Barbadoes were brought forward, 241 casks; the whole went off heavily, at a further reduction of 1s. particularly the good sugars; good white, 69s. 6d. a 71s. 6d.; the others 62s. a 68s.

The refined market was heavy last week, yet the very reduced prices prevented the holders from selling; large lumps, 78s. a 80s. were with difficulty to be purchased, as a very general opinion prevailed that the low prices would attract the attention of the exporters, and that no further reduction could be anticipated; lumps, 828. a 84s. were taken off for crushing.-Molasses are steady.

In foreign sugars, the only sale last week was about 200 chests of yellow Havannah, 30s. a 32s.

The public sale of Pernambuco and Bahia this forenoon consisted of damaged sugars, affording no criterion of the market prices; the whole sold exceedingly low. The Havannah sugars, 100 boxes, sold at 6s. a 7s. per cwt. lower than any previous sale, good strong white realizing only 45s. ; the middling, 42s.

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