The natural history of Aleppo, and parts adjacent

The weather at Aleppo differing but very little in any one year from another, I thought it would save a great deal of unnecessary trouble, if I gave a general account of the weather usual in every month, drawn from a meteorological register, regularly kept, with only few intermissions, for about ten years, and afterwards noted what was particular.

The barometer used in the following observations was English, and graduated according to the measure of that country. The first column denotes inches, the second 10ths of an inch.

The thermometers, (for, from accidents of breaking, several were used) except for the last two years, were small portable ones, graduated according to Farenheit’s scale; the other was larger, upon the same scale. All of them were of mercury, and (as well as the barometer) made by the accurate Mr. Bird in London.

The situation of the instruments for the years 1743, 44, 45, and those of 52 and 53, was in a little wooden kiosk⁠[486], facing the east, which projected over a narrow street that run south and north, with high buildings on each side. The sun had only access by the south-window, and that scarce an hour in the day. To this place there was a free ingress of air, the two opposite windows, and often the whole, being constantly open from the month of April till the latter end of October; and in the winter, though these windows were shut, a free access still remained by the door, and a window which opened into a passage fronting the west, the outer door of which in the day-time was always open. Add to this, that these wooden kiosks have not either their wood-work, or numerous windows, so well closed as to prevent a pretty considerable communication with the external air through the chinks.

This is the situation which appears to be much preferable to any other, and from which the general account of the weather is taken. But a multiplicity of practice rendering it impossible for me to keep the register, I was obliged to a friend, who was so kind as to take that trouble for me; and then the thermometer was placed in a vaulted south-room, which was defended from the west by two other rooms, and opposite to the window a door opened into a large vaulted hall. In the winter (particularly the forenoon) this was frequently open, and in the summer-months was shut only by a door made of lattice-work, the window being open all that season. In this country the rooms so situated are remarkably warm in winter, and cool in summer.

In this last position the thermometer must be understood to be kept from July 1746 till the end of 1747. Both these situations being within doors, were some degrees warmer than the external air in winter, as would appear from the thermometer never sinking to the freezing point even in time of frost; and they are cooler than the external air in summer, as I have found by several trials. These things were necessary to be premised, as they may account for the variations in the instrument, that are remarkable in the different situations.

JANUARY.

The weather in January is commonly either frosty or rainy. What snow falls is chiefly in this month; but it is in no great quantity, and does not lie many hours. The middle of the month is its most usual time of falling, and then it often remains frosty till the end.

Whenever rain falls, it is usually in the night, and in very heavy showers.

The winds are moderate, and mostly from the northern or eastern quarter.

The most common height of the thermometer at nine in the morning is 40 and 46, and the difference between that and three in the afternoon a gradual rise of 3 or 4 deg. In rainy days, or even such as are cloudy, this variation seldom exceeds 1 or 2 deg. and often there is none at all; and this observation holds through all the year.

FEBRUARY.

This month is for the most part as rainy as the former; with this difference, that neither rain nor fair weather continue so many days together, but change from one to the other every four or five days. A little snow often falls in this month, and commonly there are a few frosty days. It is very often cloudy, though no rain falls, particularly in the afternoon; but they are light, white clouds. At such times the air without doors is moderately warm. The winds are much as in the preceding month, till towards the end, and then it sometimes blows hard westerly.

The first fortnight, the usual morning-height of the thermometer is from 42 to 47; the variation between the morning and evening observation, 1, 2, or 3 deg. In the last fortnight, when there happens no frost, it gradually rises to about 50, and the difference between morning and evening commonly 4 or 5.

MARCH.

A good deal of rain falls in the month of March; but it is generally in short, hard showers, and often accompanied with thunder. At such times the weather is dark and gloomy; but for the greater part it is clear, only a few white light clouds. The weather begins to be hot in the open air.

The winds are stronger than in the preceding months, and blow much oftener westerly.

The common height of the thermometer in the morning is in the beginning of the month as in the end of the last; about the middle, 52; the end, 56 to 58. The difference between morning and evening observations become more considerable as the month advances; in the beginning, commonly 5; the end, 8 to 9. If it rains, the variation is very inconsiderable, as has been mentioned before.

APRIL.

This month is in general fair, clear weather, with white, light clouds in the afternoon; seldom dark or cloudy, except when it rains, which it does in hard thunder-showers as in the last month, but not so often. There are commonly a few close, hazey days; these happen when there are light breezes northerly or easterly; but the winds in general are fresh westerly.

The days begin to grow very hot, but the mornings and evenings as yet remain cool.

The mercury in the thermometer has its morning-station gradually raised from 60 to 66 as the month advances, and the variation 8 to 10 between the morning and evening observation, except when it rains.

MAY.

May has generally one or two hard showers of rain, sometimes accompanied with hail, and often thunder; at others, the weather is serene, with very few clouds, and those light and white.

The weather begins to grow very warm in this month, particularly when calm, or the wind northerly or easterly; but the wind for much the greater part is fresh, and westerly. And here it will not be amiss to observe, that, during the whole of the summer, the westerly winds have a considerable influence over the thermometer. When they are weak, the heat encreases; if calm, it becomes still hotter; but even then not so hot as when a northerly or easterly wind blows, which raises the mercury several degrees, and makes the air very disagreeable. See p. 14.

The usual station of the mercury in the thermometer is at the beginning 70, and it gradually rises, as the month advances, to 76 or 80. The variation between the morning and evening observation rises also from 6 to 9.

JUNE.

This month is serene throughout, seldom so much as a few flying clouds to be seen. It is very rare that even so much as one shower of rain falls, and that at most but for a few minutes.

The westerly winds reign chiefly in this month; and freshening after mid-day, often continue through the night, which allay the extreme heat, now become very troublesome.

The morning-height of the mercury, at seven o’clock, gradually encreases with the month, from 76 to about 80; as that of the afternoon, at four o’clock, does from 84 to 92.

JULY.

July differs very little from the former month; the weather constantly serene.

The westerly winds usually blow fresh; but, if they fail, it becomes excessive hot.

Eighty, is the common height of the mercury, in the morning, at the beginning of the month, as 85, 86 is at the end. The difference between the morning and evening observation, 8 or 10.

AUGUST.

Till about the 20th, August is exactly like the two preceding months: from that to the end, there usually appear a number of white clouds, but larger than any that accidentally appear in other summer-months. These are commonly termed the Nile clouds; and from this time, the dews (which are scarce ever observed in the two preceding months) begin to fall in the nights; but they are not very considerable.

The height of the thermometer, till the clouds appear, is pretty much the same as in that of last month; but, whenever they come, they commonly sink it 4 or 5 degrees.

SEPTEMBER.

For the first fortnight this month is like the former, or rather more sultry, as the wind seldom blows strong. If no rain falls, this weather continues all the month; but usually between the 15th and 25th dark, gloomy clouds arise; and a squal, in the nature of a whirlwind, blows from the westward, bringing with it a great cloud of dust that covers the whole city. This prognosticates rain, and in one or two days more some heavy showers fall, either in the city, or not far off. These are called the first rains; and though they are usually inconsiderable, yet the air is much cooled, and the remainder of the month rendered very pleasant.

Seldom a night passes without much lightening in the north-west quarter, but not attended by thunder. When this lightening appears in the west or south-west points, it is a sure sign of the approaching rain, which is often followed by thunder.

The winds in September are westerly, but often not more than light breezes.

In the beginning of this month, the usual morning-height of the thermometer is much as in the end of August; the variation between the morning and evening observation rather more considerable. The falling of rain sinks it 3 or 4 degrees, and it usually keeps falling all the month till it gets to 65. The variation in one day seldom then, exceeds 3 or 4, and just at the falling of the rain much less, perhaps 1 or 2.

OCTOBER.

Till the second rains fall in October, the weather is serene, cool, and rather more pleasant than at any other time of the year; afterwards it becomes more variable. These rains are usually regulated by those in September, being between twenty and thirty days after them; and, like them also, the quantity varies considerably in different years. However, those of October are seldom less than three or four days; but it must not be understood that it continues a constant rain during the whole of those days.

The winds are rarely strong in this month, but are commonly variable.

The morning-height of the thermometer, till the rains fall, is usually about 72; the difference between the morning and evening observation, 5 or 6. After the falling of the rains it gradually sinks to 60. The variation then in one day is seldom more than 3 or 4, on the rainy days commonly less.

NOVEMBER.

November may be reckoned one of the rainy months, though frequently there is an interval of very fine weather. The number of rainy days rarely exceed seven or eight, and most of them only a few heavy showers. It is unusual to see snow fall in this month; but after the first fortnight it is generally frosty in the morning when the weather is serene.

The winds are variable, seldom strong, but more inclined to the north and east than any of the other quarters.

As the month advances, the mercury in the thermometer gradually falls from 60 to 50; the former being its usual morning-height at the beginning, as the latter is at the end. The variation in one day, from 5 to 2; but on rainy days there is very often no variation at all.

DECEMBER.

This is usually a rainy month, and much more cloudy, foggy weather in the intervals than in the preceding, consequently not near so agreeable. The greatest number of rainy days mentioned in the register is 16, the fewest 6, commonly 8 or 9.

There is always more or less frosty weather in this month, and frequently a little snow. This falls out commonly after or about the end of the first fortnight, and with it commences the cold weather.

The winds are, as in the preceding month, commonly easterly or northerly, and seldom strong.

Forty-six is the common height of the thermometer through this month. The difference between the morning and evening observation, when it does not rain, is often 3.