PART II.. Observations on the Epidemical Diseases in the City of _aleppo_.

OBSERVATIONS on the Epidemical Diseases in the City of Aleppo.

CHAP. I.

Observations on the WEATHER in General.

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, 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.

Therm. Barom. Greatest height 57 Greatest 29 3 Greatest variation of therm. Least 34 Least 28 6 in one day, 4 deg.

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.

Therm. Barom. Greatest height 55 Greatest 29 3 Greatest difference of therm. Least 40 Least 28 4 in one day, 8 deg.

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.

Therm. Barom. Greatest height 67 Greatest 29 Difference in the thermometer Least 44 Least 28 6 in one day, 9 deg.

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.

Therm. Barom. Greatest height 82 Greatest 29 1 Difference in the thermometer Least 51 Least 28 5 in one day, 10 deg.

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.

Therm. Barom. Greatest height 92 Greatest 29 Greatest variation of the Least 67 Least 28 6 therm. in one day, 10 deg.

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.

Therm. Barom. Greatest height 96 Greatest 29 Greatest variation of therm. Least 76 Least 28 5 in one day, 12 deg.

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.

Therm. Barom. Greatest height 101 Greatest 28 9 Greatest variation of therm. Least 77 Least 28 5 in one day, 11 deg.

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.

Therm. Barom. Greatest height 97 Greatest 29 Greatest variation in the Least 74 Least 28 4 therm. in one day, 10 deg.

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.

Therm. Barom. Greatest height 92 Greatest 29 Greatest difference of the Least 62 Least 28 6 therm. in one day, 12 deg.

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.

Therm. Barom. Greatest height 84 Greatest 29 Greatest difference of the Least 51 Least 28 6 therm. in one day, 10 deg.

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.

Therm. Barom. Greatest height 65 Greatest 29 1 Greatest variation of the Least 44 Least 28 4 therm. in one day, 8 deg.

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.

Therm. Barom. Greatest height 55 Greatest 29 1 Greatest difference of the Least 40 Least 28 4 therm. in one day, 5 deg.

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.

CHAP. II.

Of the WEATHER from the Year 1742 to 1747, and of the Years 1752 and 1753.

A. D. MDCCXLII.

The winter of this year was more severe than usual in this country, and much less rain in March and April than is customary at that season.

About the end of April the weather became very warm, and continued so till the 20th of May; from which time, till the 22d of June, it grew rather cool for the season of the year, the air being refreshed by strong westerly breezes.

The 22d of June, the wind changed to north-west, and was very moderate; upon which the weather became exceeding hot, and continued so all that month, and for the first ten days in July. The remainder of the summer was such as is common in this country, without any of the hot easterly winds.

On the 25th of September the first rains fell, and continued only one day; after which the weather was extremely pleasant till the end of October; when the second rains fell, and continued a few days. Upon their ceasing, it set in fair and serene till the 14th of December; when a small shock of an earthquake was felt, and a hard frost began, which continued all that month.

For want of proper instruments, the changes of heat and cold this year are here represented according to what they appeared to our senses.

A. D. MDCCXLIII.

From the beginning of January till the middle, a great deal of snow fell, the frost continued, and the air was exceeding cold; the thermometer being but once above 40 in the evening, and in the morning commonly 36, once 34, on the third at 9, A. M. A few days of fair, pleasant weather succeeded this cold, and then began violent rains, which continued during the remainder of the month.

The rains were almost constant till the 20th of February; the latter part of which month was fair, pleasant weather.

March set in with variable spring-weather, (though somewhat cooler than usual), which continued till the 23d; from which time till the end a great quantity of rain, hail, and thunder.

April was fair (except one thunder-shower) till the 19th; during which the weather was pretty warm, with a sort of haziness in the air. The 20th and 21st, it blew very hard from the south-west, with much rain, and the weather became unusually cool for the season. The mercury in the thermometer, which had before commonly rose to 74 in the afternoon, seldom afterwards getting up so high as 66 during the whole month, which was attended with a good deal of rain and thunder, some hail, and the wind generally fresh westerly.

May (except on the 13th and 23d, when some severe thunder-showers fell) was fair, pleasant weather, and much cooler than usual. The thermometer was unfortunately broke this month; so that from this time till May following, the observations were made by a large thermometer, filled with spirits, which showed distinctly the changes of heat and cold, but was not upon any known scale.

The beginning of June was fair and cool weather for the season. On the 10th it began to be hot; and, notwithstanding strong westerly winds, and often flying clouds, the air was very hot during the rest of the month. On the 12th, at 8 P. M. were felt two small shocks of an earthquake. The sky was at that time serene, and it blew fresh.

On the night between the 1st and 2d of July, some severe thunder-showers fell; a thing very extraordinary at this season. During the whole of the month, the westerly wind blew fresh, and generally continued great part of the night, by which means the air was rendered remarkably cool.

This chill weather continued a few days in August; but the remainder of that month, the winds, though westerly, being moderate, and ceasing a little after sunset, together with its succeeding such cool weather, made it seem uncommonly warm, though from the thermometer it appeared that the heat was not in reality greater than in other years. On the 19th, at half an hour after eleven o’clock at night, was felt a small shock of an earthquake. The sky was at that time serene, and little wind stirring.

The beginning of September was hot, as in August; but on the 10th it became sultry, particularly in the night, and continued so till the 18th at night, when the first rains began to fall; and though they were but moderate, they rendered the remainder of the month quite cool.

Though it rained a little on the 8th of October, and continued cloudy for several days; yet the second rains did not, properly speaking, fall till the 23d, when they were plentiful, and continued three days. The remainder of that month, and all the rest of the year, afforded nothing remarkable.

A. D. MDCCXLIV.

The snow which fell on the 5th of January lay six inches deep, and continued for several days in places shaded from the sun; which is not usual in this country; the quantity that fell in this month was likewise somewhat extraordinary.

February and March had nothing in them different from other years.

April was more rainy than customary. On the 28th, at half an hour after one in the morning, were two pretty brisk shocks of an earthquake, and at six in the evening another.

May and July were as usual in a moderate summer; but June had more northerly winds, and was hotter than common; the usual height of the thermometer being 95.

From the first week in August, several days of easterly winds rendered the air unusually hot, which by a very singular, though but small, shower of rain on the 30th, was cooled for a few days; the thermometer, P. M. falling from 92 to 83.

The first rains were ushered in by the accustomed squall of wind on the 4th of September at night, and were violent for a few hours, but did not cool the air. On the 20th and 22d, one shower of rain fell, and rendered it more cool; and the plentiful rain on the evening of the 23d, and greatest part of the day on the 24th, completed it.

On the 16th of October, at night, the second rains fell, with a good deal of thunder, and on the 19th some more; after which the rest of the year afforded nothing that was remarkable.

A. D. MDCCXLV.

This year had nothing uncommon in the weather till the 12th of March, when it became cold; and an unusual frost, with, a north-east wind for a few days, nipped most of the blossoms on the trees; the mercury in the thermometer after noon being rarely above 54, whereas before it was at 62.

April was remarkably dry, having but one shower of rain, on the 6th. May and June had nothing extraordinary.

July, except a few days at the latter end, and all August, not being refreshed with the westerly breezes, and having several days of easterly wind, particularly the middle of August, were extremely hot; the afternoons height of the thermometer being often 100, and twice 101.

The first rains were very moderate, and fell on the 10th September, being as usual preceded by a squal of wind. The second rains fell heavy and seasonable, about the middle of October; from which time happened nothing singular all the rest of the year.

A. D. MDCCXLVI.

The 4th, 5th, and 6th of January this year, it snowed almost continually; so that it lay in the streets above a foot thick, which is very uncommon. It was not all thaw’d in the city for some days; and in such places abroad where the sun-beams did not reach, there was still some lying on the 13th. From this time till June the weather was as usual.

It began to blow very hard westerly on the 13th June, and the wind brought along with it many clouds, which let fall two small showers of rain on the 14th, one at 10 A. M. the other at 7 P. M. which sunk the mercury in the thermometer from 84, its usual afternoon’s height, to 76 three fourths.

August had none of the usual cloudy weather; yet the rest of the summer had nothing in it particular.

Though it began to be cloudy on the 4th of September, and continued so for a few days, and even thundered; yet no rain fell till the 11th in the afternoon, and then only a gentle shower of about an hour, which sunk the thermometer from 82 and an half, its common afternoon’s height, to 77. It soon however rose again; and the wind being easterly or northerly from the 20th to the end of the month, the weather was unusually warm; the afternoon height of the mercury being 85 or 86.

In the month of October there fell but one shower of rain, the 25th P. M. so that the thermometer kept high all the month, and the weather was extremely pleasant.

On the 2d and 3d of November the rains fell plentifully; and, through the whole of this and the succeeding month, more fell than is usual in other years. There did not happen either frost or snow.

A. D. MDCCXLVII.

From the beginning of January till the end of March, the winds were much higher than usual at that season, neither was there any frost or snow; but more rain fell in January and February than is common, and the weather in general was bleak and unpleasant. The rest of the year till September was mild, and very moderate.

Though it was cloudy, and threatened rain about the 20th of September, yet none fell in this month at Aleppo; so the thermometer’s evenings height kept up at 82 till the end of the month.

The whole of October was clear and settled weather, except one thunder-shower on the 13th, (which sunk the mercury in the thermometer from 81 to 73) a small shower on the 22d, and a gentle rain the whole of the 24th.

On the 7th of November the rains began to fall plentifully, the weather became as in other years, but there was no frost in this month.

December was rather more foggy than common, without either frost or snow.

Being, for want of leisure, prevented from giving a particular account of the epidemic diseases from 1748 to 1751, that of the weather is also omitted.

The change of stile from the Julian to the Gregorian rendering references to the general account of the weather, which were made according to the Julian calendar, indistinct, I conceived it necessary to give the weather of the years 1752 and 1753 compleat.

It is true that the short method formerly used might have served till September, as the act of parliament did not take place till the 3d of that month: but, besides the want of uniformity that would have attended a change in the method before the year was out, I thought, that, if there were any who should make an objection to the former, this would make them some atonement; and that it could be disagreeable to none, more especially as the epidemic fevers of those two years changed their appearances so remarkably according to the season.

The thermometer used, till noted otherwise, was the large one, and the situation during the whole two years in the wooden kiosk. Where-ever a rainy day occurs, with one ′, it is to be understood that a small shower or two happened on that day; ‴ denotes violent rains, and ″ an intermediate degree of rain.

A. D. MDCCLII.

JANUARY.

The first week of this month cloudy and rainy; from the 8th to the 29th continued clear, fair weather, with some light clouds now and then intervening.

Rainy Days.

1st and 4th ″ at night, 5th ‴, 6th ″ at night, with squalls of wind, 7th and ″ 29th in the night, 30th ‴, and 31st ‴.

Greatest height of the thermometer 56 on the 28th and 29th, at 3 P. M. Least height 40 on the 10th and 11th, at 9 A. M.

Greatest height of the barometer 29 1 on the 9th. Least height 28 5 on the 4th.

In the first fortnight, the mercury in the thermometer never rose above 50. Through the whole month, the most general height at nine in the morning was 46, from which time it usually rose 3 or 4 degrees; so that at 3 P. M. it stood at 49 or 50, except in rainy weather, when the variation was less considerable, and there was frequently none at all.

FEBRUARY.

Light clouds were more frequent in this month than in the former; the weather in the afternoon often became overcast; the three last days serene; the rain fell mostly in the night, and in violent showers.

Rainy Days.

7th, begun in the evening, and continued till the 8th ″ in the forenoon, 9th ″ in the night, 10th ″ A. M. 22d ′, 23d ‴ in the night, and 24th ′ in the forenoon.

Greatest height of the thermometer 53 on the 19th, at 3 P. M. Least height 45 several days.

Greatest height of the barometer 28 9 for the greatest part of the last fortnight. Least height 28 3 on the 11th P. M.

The most common height of the thermometer in the morning was 48, its variation in the beginning of the month 3, and in the middle and latter