Chapter III: Preface (3)

This account of the variableness of the weather in winter, does not apply to every part of Pennsylvania. There is a line about the 41° of the state, beyond which the winters are steady and regular, insomuch that the earth there is seldom without a covering of snow during the three winter months. In this line the climate of Pennsylvania forms a union with the climate of the eastern and northern states.

The time in which frost and ice begin to show themselves in the neighbourhood of Philadelphia, is generally about the latter end of October or the beginning of November. But the intense cold seldom sets in till about the the 20th or 25th of December; hence the common saying, "as the day lengthens, the cold strengthens." The coldest weather is commonly in January. The navigation of the river Delaware, after being frozen, is seldom practicable for large vessels, before the first week in March.

As in summer there are often days in which fires are agreeable, so there are sometimes days in winter in which they are disagreeable. Vegetation has been observed in all the winter months. Garlic was tasted in butter in January, 1781. The leaves of the willow, the blossoms of the peach tree, and the flowers of the dandelion and the crocus, were all seen in February, 1779; and I well recollect, when a school-boy, to have seen an apple orchard in full bloom, and small apples on many of the trees, in the month of December.

A cold day in winter is often succeeded by a moderate evening. The coldest part of the four and twenty hours, is generally at the break of day.

In the most intense cold which has been recorded in Philadelphia, within the last twenty years, the mercury stood at 5° below 0. But it appears from the accounts published by Messieurs Mason and Dixon, in the 58th volume of the Transactions of the Royal Society of London, that the mercury stood at 22° below 0, on the 2d of January, 1767, at Brandywine, about thirty miles to the westward of Philadelphia. They inform us, that on the 1st of the same month, the mercury stood at 20°, and on the day before at 7° below 0. I have to lament that I am not able to procure any record of the temperature of the air in the same year in Philadelphia. From the variety in the height and quality of the soil, and from the difference in the currents of winds and the quantity of rain and snow which fall in different parts of the state, it is very probable this excessive cold may not have extended thirty miles from the place where it was first perceived.

The greatest degree of heat upon record in Philadelphia, is 95°.

The standard temperature of the air in the city of Philadelphia is 52-1/2°, which is the temperature of our deepest wells, as also the mean heat of our common spring water.

The spring in Pennsylvania is generally less pleasant than in many other countries. In March the weather is stormy, variable, and cold. In April, and sometimes in the beginning of May, it is moist, and accompanied by a degree of cold which has been called _rawness_, and which, from its disagreeable effects upon the temper, has been called the _sirocco_ of this country. From the variable nature of the weather in the spring, vegetation advances very differently in different years. The colder the spring, the more favourable it proves to the fruits of the earth. The hopes of the farmer from his fruit-trees in a warm spring are often blasted by a frost in April and May. A fall of snow is remembered with regret by many of them, on the night between the 3d and 4th of May, in the year 1774; also on the morning of the 8th of May, 1803. Such was its quantity on the latter day, that it broke down the limbs of many poplar trees. This effect was ascribed to its not being accompanied with any wind. The colder the winter, the greater delay we generally observe in the return of the ensuing spring.

Sometimes the weather during the spring months is cloudy and damp, attended occasionally with a gentle fall of rain resembling the spray from a cataract of water. A day of this kind of weather is called, from its resemblance to a damp day in Great-Britain, "an English day." This damp weather seldom continues more than three or four days. The month of May, 1786, will long be remembered, for having furnished a very uncommon instance of the absence of the sun for fourteen days, and of constant damp or rainy weather.

The month of June is the only month in the year which resembles a spring month in the southern countries of Europe. The weather is then generally temperate, the sky is serene, and the verdure of the country is universal and delightful.

The autumn is the most agreeable season in the year in Pennsylvania. The cool evenings and mornings, which generally begin about the first week in September, are succeeded by a moderate temperature of the air during the day. This kind of weather continues with an increase of cold scarcely perceptible, till the middle of October, when the autumn is closed by rain, which sometimes falls in such quantities as to produce destructive freshes in the rivers and creeks, and sometimes descends in gentle showers, which continue, with occasional interruptions by a few fair days, for two or three weeks. These rains are the harbingers of the winter; and the Indians have long ago taught the inhabitants of Pennsylvania, that the degrees of cold during the winter, are in proportion to the quantity of rain which falls during the autumn[31].

[31] I cannot help agreeing with Mr. Kirwan, in one of his remarks
upon the science of meteorology, in the preface to his estimate
of the temperature of different latitudes. "This science (says
he), if brought to perfection, would enable us at least to
foresee those changes in the weather which we could not prevent.
Great as is the distance between such knowledge and our own
present attainments, we have no reason to think it above the
level of the powers of the human mind. The motions of the
planets must have appeared as perplexed and intricate to those
who first contemplated them; yet, by persevering industry, they
are now known to the utmost precision. The present is (as the
great Leibnitz expresses it) in every case pregnant with the
future, and the connection must be found by long and attentive
observation."

The influence which the perfection of this science must have upon
health, agriculture, navigation, and commerce, is too obvious to
be mentioned.

From this account of the temperature of the air in Pennsylvania, it is evident that there are seldom more than four months in which the weather is agreeable without a fire.

In winter the winds generally come from the north-west in _fair_, and from the north-east in _wet_ weather. The north-west winds are uncommonly dry as well as cold. It is in consequence of the violent action of these winds that trees have uniformly a thicker and more compact bark on their northern than on their southern exposures. Even brick houses are affected by the force and dryness of these north-west winds: hence it is much more difficult to demolish the northern than the southern walls of an old brick house. This fact was communicated to me by an eminent bricklayer in the city of Philadelphia.

The winds in fair weather in the spring, and in warm weather in the summer, blow from the south-west and from west-north-west. The _raw_ air before-mentioned comes from the north-east. The south-west winds likewise usually bring with them those showers of rain in the spring and summer which refresh the earth. They moreover moderate the heat of the weather, provided they are succeeded by a north-west wind. Now and then showers of rain come from the west-north-west.

There is a common fact connected with the account of the usual winds in Pennsylvania, which it may not be improper to mention in this place. While the clouds are seen flying from the south-west, the _scud_, as it is called, or a light vapour, is seen at the same time flying below the clouds from the north-east.

The moisture of the air is much greater than formerly, occasioned probably by the exhalations which in former years fell in the form of snow, now descending in the form of rain. The depth of the snow is sometimes between two and three feet, but in general seldom exceeds between six and nine inches.

Hail frequently descends with snow in winter. Once in four or five years large and heavy showers of hail fall in the spring and summer. They generally run in narrow veins (as they are called) of thirty or forty miles in length, and two or three miles in breadth. The heaviest shower of hail that is remembered in Philadelphia, did not extend in breadth more than half a mile north and south. Some of the stones weighed half an ounce. The windows of many houses were broken by them. This shower fell in May, 1783.

From sudden changes in the air, rain and snow often fall together, forming what is commonly called _sleet_.

In the uncultivated parts of the state, the snow sometimes lies on the ground till the first week in April. The backwardness of the spring has been ascribed to the passage of the air over the undissolved beds of snow and ice which usually remain, after the winter months are past, on the north-west grounds and waters of the state, and of the adjacent country.

The dissolution of the ice and snow in the spring is sometimes so sudden as to swell the creeks and rivers in every part of the state to such a degree, as not only to lay waste the hopes of the husbandman from the produce of his lands, but in some instances to sweep his barns, stables, and even his dwelling house into their currents[32]. The wind, during a general thaw, comes from the south-west or south-east.

[32] The following account of the thaw of the river Susquehannah, in
the spring of 1784, was published by the author in the Columbian
Magazine, for November, 1786. It may serve to illustrate a fact
related formerly in the history of the winters in Pennsylvania,
as well as to exhibit an extraordinary instance of the
destructive effects of a sudden thaw.

"The winter of 1783-4 was uncommonly cold, insomuch that the
mercury in Fahrenheit's thermometer stood several times at 5
degrees below 0. The snows were frequent, and, in many places,
from two to three feet deep, during the greatest part of the
winter. All the rivers in Pennsylvania were frozen, so as to
bear waggons and sleds with immense weights. In the month of
January a thaw came on suddenly, which opened our rivers so as to
set the ice a-driving, to use the phrase of the country. In the
course of one night, during the thaw, the wind shifted suddenly
to the north-west, and the weather became intensely cold. The
ice, which had floated the day before, was suddenly obstructed;
and in the river Susquehannah, the obstructions were formed in
those places where the water was most shallow, or where it had
been accustomed to fall. This river is several hundred miles in
length, and from half a mile to a mile and a half in breadth, and
winds through a hilly, and in many places a fertile and highly
cultivated country. It has as yet a most difficult communication
with our bays and the sea, occasioned by the number and height
of the falls which occur near the mouth of the river. The ice in
many places, especially where there were falls, formed a kind
of dam, of a most stupendous height. About the middle of March
our weather moderated, and a thaw became general. The effects
of it were remarkable in all our rivers; but in none so much as
in the river I have mentioned. I shall therefore endeavour in a
few words to describe them. Unfortunately the dams of ice did
not give way all at once, nor those which lay nearest to the
mouth of the river, first. While the upper dams were set afloat
by the warm weather, the lower ones, which were the largest, and
in which, of course, the ice was most impacted, remained fixed.
In consequence of this, the river rose in a few hours, in many
places, above 30 feet, rolling upon its surface large lumps of
ice, from 10 to 40 cubic feet in size. The effects of this sudden
inundation were terrible. Whole farms were laid under water.
Barns, stables, horses, cattle, fences, mills of every kind, and,
in one instance, a large stone house, 40 by 30 feet, were carried
down the stream. Large trees were torn up by the roots; several
small islands, covered with woods, were swept away, and not a
vestige of them was left behind. On the barns which preserved
their shape, in some instances, for many miles were to be seen
living fowls; and, in one dwelling, a candle was seen to burn
for some time, after it was swept from its foundation. Where the
shore was level, the lumps of ice, and the ruins of houses and
farms, were thrown a quarter of a mile from the ordinary height
of the river. In some instances, farms were ruined by the mould
being swept from them by the cakes of ice, or by depositions of
sand; while others were enriched by large depositions of mud.
The damage, upon the whole, done to the state of Pennsylvania by
this fresh, was very great. In most places it happened in the day
time, or the consequences must have been fatal to many thousands."

"I know of but one use that can be derived from recording the
history of this inundation. In case of similar obstructions of
rivers, from the causes such as have been described, the terrible
effects of their being set in motion by means of a general thaw
may in part be obviated, by removing such things out of the
course of the water and ice as are within our power; particularly
cattle, hay, grain, fences, and farming utensils of all kinds."

The air, when dry in Pennsylvania, has a peculiar elasticity, which renders the heat and cold less insupportable than the same degrees of both are in moister countries. It is in those cases only when summer showers are not succeeded by north-west winds, that the heat of the air becomes oppressive and distressing, from being combined with moisture.

From tradition, as well as living observation, it is evident, that the waters in many of the creeks in Pennsylvania have diminished considerably within the last fifty years. Hence many mills, erected upon large and deep streams of water, now stand idle in dry weather; and many creeks, once navigable in large boats, are now impassable even in canoes. This diminution of the waters has been ascribed to the application of a part of them to the purpose of making meadows.

The mean elevation of the barometer in Philadelphia, is about 30 inches. The variations in the barometer are very inconsiderable in the greatest changes of the weather, which occur in the city of Philadelphia. During the violent and destructive storm which blew from the south-west on the 11th of November, 1788, it suddenly fell from 30 to 29-3/10. Mr. Rittenhouse informs me, that long and faithful observations have satisfied him, that the alterations in the height of the mercury in the barometer do not _precede_ but always _succeed_ changes in the weather. It falls with the south and south-west, and rises with the north and north-west winds.

The quantity of water which falls in rain and snow, one year with another, amounts to from 24 to 36 inches. But to complete the account of variable qualities in the climate, it will be necessary to add, that our summers and autumns are sometimes marked by a _deficiency_, and sometimes by an _excessive_ quantity of rain. The summer and autumn of 1782 were uncommonly dry. Near two months elapsed without a single shower of rain. There were only two showers in the whole months of September and October. In consequence of this dry weather, there was no second crop of hay. The Indian corn failed of its increase in many places, and was cut down for food for cattle. Trees newly planted, died. The pasture fields not only lost their verdure, but threw up small clouds of dust when agitated by the feet of men, or beasts. Cattle in some instances were driven many miles to be watered, every morning and evening. It was remarked during this dry weather, that the sheep were uncommonly fat, and their flesh well tasted, while all the other domestic animals languished from the want of grass and water. The earth became so inflammable in some places, as to burn above a foot below its surface. A complete consumption of the turf by an accidental fire kindled in the adjoining state of New-Jersey, spread terror and distress through a large tract of country. Springs of water and large creeks were dried up in many parts of the state. Rocks appeared in the river Schuylkill, which had never been observed before, by the oldest persons then alive. On one of them were cut the figures 1701. The atmosphere, during part of this dry weather, was often filled, especially in the mornings, with a thin mist, which, while it deceived with the expectation of rain, served the valuable purpose of abating the heat of the sun. A similar mist was observed in France by Dr. Franklin, in the summer of 1782. The winter which succeeded it was uncommonly cold in France, as well as in Pennsylvania. I am sorry that I am not able to furnish the mean heat of each of the summer months. My notes of the weather enable me to add nothing further upon this subject, than that the summer was "uncommonly cool."

The summer of the year 1788 afforded a remarkable instance of _excess_ in the quantity of rain which sometimes falls in Pennsylvania. Thirteen days are marked with rain in July, in the records of the weather kept at Spring-Mill. There fell on the 18th and 19th of August seven inches of rain in the city of Philadelphia. The wheat suffered greatly by the constant rains of July in the eastern and middle parts of the state. So unproductive a harvest in grain, from wet weather, had not been known, it is said, in the course of the last 70 years. The heat of the air, during these summer months was very moderate. Its mean temperature at Spring-Mill was 67,8 in June, 74,7 in July, and only 70,6 in August.

It is some consolation to a citizen of Pennsylvania, in recording facts which seem to militate against our climate, to reflect that the difference of the weather, in different parts of the state, at the same season, is happily accommodated to promote an increase of the same objects of agriculture; and hence a deficiency of crops has never been known in any one year throughout the _whole_ state.

The aurora borealis and meteors are seen occasionally in Pennsylvania. In the present imperfect state of our knowledge of their influence upon the human body, it will be foreign to the design of this history of our climate to describe them.

Storms and hurricanes are not unknown in Pennsylvania. They occur once in four or five years, but they are most frequent and destructive in the autumn. They are generally accompanied by rain. Trees are torn up by the roots, and the rivers and creeks are sometimes swelled so suddenly as to do considerable damage to the adjoining farms. The wind, during these storms, generally blows from the south-east and south-west. In the storms which occurred in September, 1769, and in the same month of the year 1785, the wind veered round contrary to its usual course, and blew from the north.

After what has been said, the character of the climate of Pennsylvania may be summed up in a few words. There are no two successive years alike. Even the same successive seasons and months differ from each other every year. Perhaps there is but one steady trait in the character of our climate, and that is, it is uniformly variable.

To furnish the reader with a succinct view of the weather in Pennsylvania, that includes all the articles that have been mentioned, I shall here sub-join a table containing the result of meteorological observations made near the river Schuylkill, for one year, in the neighbourhood of Philadelphia, by an ingenious French gentleman, Mr. Legeaux, who divides his time between rural employments, and useful philosophical pursuits. This table is extracted from the Columbian Magazine, for February, 1788. The height of Spring-Mill above the city of Philadelphia, is supposed to be about 70 feet.

|====================================================================|
| METEOROLOGICAL OBSERVATIONS, made at SPRING-MILL, |
| 13 miles NNW of Philadelphia. Result of the year 1787. |
|====================================================================|
| | THERMOMETER. | BAROMETER. | PREVAILING |
| | of | de | | WIND. |
| MONTH. |_Fahrenheit_,| _Reaumur_, | mean height | |
| | mean degree |degrés moyens| | |
| | D. 1/16 O | D. 1/10 O |in. pts. 1/16| |
|----------+-------------+-------------+-------------+---------------|
|January | 35 1 | 1 4 | 29 9 9 |Variable still |
|February | 33 8 | 8 | 29 9 9 |NE |
|March | 45 1 | 5 8 | 29 9 7 |W |
|April | 54 3 | 9 9 | 29 9 6 |Still, SW |
|May | 61 2 | 13 | 29 9 2 |Still, WSW |
|June | 70 7 | 17 2 | 29 8 2 |WNW |
|July | 72 2 | 17 9 | 29 9 10 |WWSW var. |
|August | 74 5 | 18 9 | 29 10 6 |W |
|September | 64 7 | 14 5 | 29 10 4 |WNW |
|October | 51 1 | 8 5 | 29 11 9 |WNW vari. |
|November | 45 1 | 5 8 | 29 11 1 |Still, vari. |
|December | 34 | 9 | 29 7 7 |WNW |
|----------+-------------+-------------+-------------+---------------|
| |10 Feb. |10 Feb. D. du| 8 Mar. | |
| RESULT. |greatest D. |plus. gr. | greatest | |
| |of cold. |froid. | elevation. | |
| | 5 | 12 0 | 30 10 | |
| |-------------+-------------+-------------| |
| |3 July |3 July plus |2 Febr. least| WNW |
| |greatest D. |G. D. de |elevation. | |
| |of heat. |chaud. | | |
| | 96 1 | 28 5 | 29 | |
| |-------------+-------------+-------------| |
| |Variation. | Variation. |Variation. | |
| | 91 1 | 40 5 | 1 10 | |
|----------|-------------+-------------+-------------|---------------|
| |Temperature. |Temperature. |Mean elevat. | |
| | 53 5 | 9 6 | 20 9 9 | |
|====================================================================|
| MONTH. | DAYS of | WATER | WEATHER. Key for left |
| | [Key | of RAIN | A=aur. bor. |
| | at right] | and SNOW. | R=rain Th=thunder |
| |A|R |Th|S |T|in. pts. 1/16| S=snow T=tempest |
|----------+-+--+--+--+-+-------------+------------------------------|
|January | | 7| 1| 4| | 3 10 10 |Fair, still, cold, and snow. |
|February | | 3| | 3|2| 3 7 3 |Fair, overcast. |
|March | | 6| | 3| | 2 4 2 |Fair, windy. |
|April | | 3| 2| 1|2| 1 2 13 |Fair, and very dry. |
|May |1|14| 6| |2| 4 11 4 |Foggy, cold, and wet. |
|June | | 9| 1| | | 1 10 4 |Very fair & growing weather. |
|July |1| 5| 2| | | 3 1 11 |Fair, and overcast. |
|August | |11| 4| |1| 5 2 3 |Very fair, and cloudy. |
|September | | 6| 1| |1| 2 7 8 |Fair weather. |
|October |1| 4| | | | 7 10 |Foggy, fair, and dry weather. |
|November |1| 5| | | | 2 6 10 |Very fair. |
|December | | | | 1|1| 9 |Very fair, and very dry. |
|----------+-+--+--+--+-+-------------+------------------------------|
| RESULT. |4|73|17|12|9|32 8 14 |TEMPERATURE OF THE YEAR 1787. |
| | | | Very fair, dry, abundant in |
| | | | every thing, and healthy. |
|====================================================================|

It is worthy of notice, how near the mean heat of the year, and of the month of April, in two successive years, are to each other in the same place. The mean heat of April, 1787, was 54°3, that of April, 1788, was 52°2. By the table of the mean heat of each month in the year, it appears that the mean heat of 1787 was 53°5 at Spring-Mill.

The following accounts of the climates of Pekin and Madrid, which lie within a few minutes of the same latitude as Philadelphia, may serve to show how much climates are altered by local and relative circumstances. The account of the temperature of the air at Pekin will serve further to show, that with all the advantages of the highest degrees of cultivation which have taken place in China, the winters are colder, and the summers warmer there than in Pennsylvania, principally from a cause which will probably operate upon the winters of Pennsylvania for many centuries to come, viz. the vicinity of an uncultivated north-west country.

"PEKIN, lat. 39° 54', long. 116° 29' W.

"By five years observations, its annual mean temperature was found to be 55° 5'.

January 20°,75 July 84°,8
February 32 August 83
March 48 September 63
April 59 October 52
May 72 November 41
June 83°,75 December 27

"The temperature of the Atlantic under this parallel is 62, but the standard of this part of the globe is the North Pacific, which is here 4 or 5 degrees colder than the Atlantic. The Yellow Sea is the nearest to Pekin, being about 200 miles distant from it; but it is itself cooled by the mountainous country of Corea, which interposes between it and the ocean, for a considerable part of its extent. Besides, all the northern parts of China (in which Pekin lies) must be cooled by the vicinity of the mountains of Chinese Tartary, among which the cold is said to be excessive.

"The greatest cold usually experienced during this period was 5°, the greatest heat, 98°: on the 25th of July, 1773, the heat arose to 108° and 110°: a N. E. or N. W. wind produces the greatest cold, a S. or S. W. or S. E. the greatest heat[33]."

[33] "6. Mem. Scav. Etrang. p. 528."

"MADRID, lat. 40° 25', long. 3° 20' E.

The usual heat in summer is said to be from 75° to 85°; even at night it seldom falls below 70°; the mean height of the barometer is 27,96. It seems to be about 1900 feet above the level of the sea[34]."

[34] "Mem. Par. 1777, p. 146."

The above accounts are extracted from Mr. Kirwan's useful and elaborate estimate of the temperature of different latitudes.

The history which has been given of the climate of Pennsylvania, is confined chiefly to the country on the east side of the Allegany mountain. On the west side of this mountain, the climate differs materially from that of the south-eastern parts of the state in the temperature of the air, in the effects of the winds upon the weather, and in the quantity of rain and snow which falls every year. The winter seldom breaks up on the mountains before the 25th of March. A fall of snow was once perceived upon it, which measured an inch and a half, on the 11th day of June. The trees which grow upon it are small, and Indian corn is with difficulty brought to maturity, even at the foot of the east side of it. The south-west winds on the west side of the mountain are accompanied by cold and rain. The soil is rich, consisting of near a foot, in many places, of black mould. The roads in this country are muddy in winter, but seldom dusty in summer. The arrangement of strata of the earth on the west side, differs materially from their arrangement on the east side the mountain. "The country (says Mr. Rittenhouse, in a letter to a friend in Philadelphia[35]), when viewed from the western ridge of the Allegany, appears to be one vast extended plain. All the various strata of stone seem to lie undisturbed in the situation in which they were first formed, and the layers of stone, sand, clay, and coal, are nearly _horizontal_."

[35] Columbian Magazine, for October, 1786.

The temperature of the air on the west is seldom so hot, or so cold, as on the east side of the mountain. By comparing the state of a thermometer examined by Dr. Bedford at Pittsburg, 284 miles from Philadelphia, it appears that the weather was not so cold by twelve degrees in that town, as it was in Philadelphia, on the 5th of February, 1788.

To show the difference between the weather at Spring-Mill and in Pittsburg, I shall here sub-join an account of it, in both places, the first taken by Mr. Legeaux, and the other by Doctor Bedford.

+----------------------------------------------------------+
| METEOROLOGICAL OBSERVATIONS, made at SPRING-MILL, |
| 13 miles NNW. of Philadelphia. April, 1788. |
+-------+------------------------+-------------+-----------+
| | | | |
| | | | |
| | | | |
| | | | |
| | THERMOMETER | | |
| |-------------+----------| BAROMETER. | |
| | of | de | | |
| |_Fahrenheit_,|_Reaumur_,| mean | |
| D. | mean | degrés | height | |
| of the| degree | moyens | |PREVAILING |
| month.| D. 1/10 O | D. 1/10 O|in. pts. 1/10| WIND. |
+-------+-------------+--------+-+-------------+-----------+
| 1 | 58 1 | | 11 6 | | 29 10 5 |W. |
| 2 | 46 9 | | 6 9 | | 30 1 |Calm. |
| 3 | 40 3 | | 3 7 | | 30 3 |Changeable.|
| 4 | 51 3 | | 8 6 | | 29 11 7 |SW. |
| 5 | 51 1 | | 8 5 | | 30 7 |E. |
| 6 | 55 7 | | 10 5 | | 29 11 7 |Calm. |
| 7 | 51 3 | | 8 6 | | 30 2 |NE. |
| 8 | 42 1 | | 4 5 | | 29 11 |E. |
| 9 | 63 5 | | 14 | | 29 8 |W. |
| 10 | 46 7 | | 6 5 | | 29 10 |W. |
| 11 | 53 8 | | 9 7 | | 30 2 |W. |
| 12 | 44 5 | | 5 5 | | 29 10 |Calm. |
| 13 | 60 5 | | 12 7 | | 29 10 3 |SW. |
| 14 | 50 2 | | 8 1 | | 29 9 |E. |
| 15 | 58 1 | | 11 6 | | 29 9 7 |SW. |
+-------+----- --+---+-- -----+-+-------------+-----------+
| METEOROLOGICAL OBSERVATIONS, made at PITTSBURG, |
| 284 miles west of Philadelphia. April, 1788. |
+-------+---------+---+--------+-+-------------+-----------+
| 1 | 46 | | | | |SW. |
| 2 | 42 | | | | |NE. by N. |
| 3 | 43 | | | | |SE. |
| 4 | 64 | | | | |Calm. |
| 5 | 80 | | | | |SE. by S. |
| 6 | 52 | | | | |SW. |
| 7 | 48 | | | | |NE. by N. |
| 8 | 66 | | | | |SE. by S. |
| 9 | 56 | | | | |NW. by N. |
| 10 | 60 | | | | |SW. |
| 11 | 62 | | | | |Calm. |
| 12 | 67 | | | | |SW. |
| 13 | 62 | | | | |Calm. |
| 14 | 60 | | | | |Variable. |
| 15 | 52 | | | | |W. |
+-------+---------+---+--------+-+-------------+-----------+
+------------------------------------------------------+
| METEOROLOGICAL OBSERVATIONS, made at SPRING-MILL, |
| 13 miles NNW. of Philadelphia. April, 1788. |
+-------+-----------------------+----------------------+
| | DAYS of | |
| |aur. boreal. | |
| | |rain. | |
| | | |thunder. | |
| | | | |snow. | |
| | | | | | +-------------| |
| | | | | | | WATER. | |
| D. | | | | | | of RAIN | |
| of the| | | | | | and SNOW. | |
| month.| | | | | |in. pts. 1/16| WEATHER. |
+-------+-+-+-+-+-+-------------+----------------------+
| 1 | | | | | | |Overcast, fair. |
| 2 | | | | | | |Overcast and windy. |
| 3 | |1| | | | 1 15 |Overcast, rainy. |
| 4 | | | | | | |Overcast. |
| 5 | | | | | | |Overcast, fair. |
| 6 | |1| | | | 1 3 |Overcast, rainy. |
| 7 | |1| | | | 2 7 |Overcast, rainy. |
| 8 | |1| | | | 1 4 |Rainy. |
| 9 | | | | | | |Overcast, windy. |
| 10 | | | | | | |Fair. |
| 11 | | | | | | |Very fair. |
| 12 | |1| | | | 1 11 |Overcast, rainy. |
| 13 | | | | | | |Very fair. |
| 14 | |1| | | | 1 14 |Fair, overcast, rainy.|
| 15 | |1| | | | 2 13 |Foggy, rainy. |
+-------+-+-+-+-+-+-------------+----------------------+
| METEOROLOGICAL OBSERVATIONS, made at PITTSBURG, |
| 284 miles west of Philadelphia. April, 1788. |
+-------+-+-+-+-+-+-------------+----------------------+
| 1 | |1| | | | |Cloudy. |
| 2 | | | | | | |Clear. |
| 3 | |1| | | | |Cloudy. |
| 4 | | | | | | |Clear. |
| 5 | |1|1| | | |Cloudy. |
| 6 | |1| | | | |Cloudy. |
| 7 | | | | | | |Cloudy. |
| 8 | |1|1| | | |Cloudy. |
| 9 | | | | | | |Cloudy. |
| 10 | | | | | | |Cloudy, with wind. |
| 11 | | | | | | |Clear. |
| 12 | | | | | | |Cloudy, with wind. |
| 13 | | | | | | |Clear. |
| 14 | |1| | | | |Cloudy. |
| 15 | | | | | | |Cloudy. |
+-------+-+-+-+-+-+-------------+----------------------+

From a review of all the facts which have been mentioned, it appears that the climate of Pennsylvania is a compound of most of the climates in the world. Here we have the moisture of Britain in the spring, the heat of Africa in summer, the temperature of Italy in June, the sky of Egypt in the autumn, the cold and snows of Norway and the ice of Holland in the winter, the tempests (in a certain degree) of the West-Indies in every season, and the variable winds and weather of Great-Britain in every month of the year.

From this history of the climate of Pennsylvania, it is easy to ascertain what degrees of health, and what diseases prevail in the state. As we have the climates, so we have the health, and the acute diseases, of all the countries that have been mentioned. Without attempting to enumerate the diseases, I shall only add a few words upon the _time_ and _manner_ in which they are produced.

I. It appears from the testimonies of many aged persons, that pleurisies and inflammatory diseases of all kinds, are less frequent now than they were forty or fifty years ago.

II. It is a well known fact, that intermitting and bilious fevers have increased in Pennsylvania in proportion as the country has been _cleared of its wood_, in many parts of the state.

III. It is equally certain that these fevers have lessened, or disappeared, in proportion as the country has been _cultivated_.

IV. Heavy rains and freshes in the spring seldom produce fevers, unless they are succeeded by unseasonably warm weather.

V. Sudden changes from great heat to cold, or cool weather, if they occur before the 20th of August, seldom produce fevers. After that time, they are generally followed by them.

VI. The same state of the atmosphere, whether cold or warm, moist or dry, continued for a long time, without any material changes, is always healthy. Acute and inflammatory fevers were in vain looked for in the cold winter of 1779-80. The dry summer of 1782, and the wet summer of 1788, were likewise uncommonly healthy in the city of Philadelphia. These facts extend only to those diseases which depend upon the sensible qualities of the air, for diseases from miasmata and contagion, are less influenced by the uniformity of the weather. The autumn of 1780 was very sickly in Philadelphia, from the peculiar situation of the grounds in the neighbourhood of the city, while the country was uncommonly healthy. The dry summer and autumn of 1782 were uncommonly sickly in the country, from the extensive sources of morbid exhalations which were left by the diminution of the waters in the creeks and rivers.

VII. Diseases are often _generated_ in one season and _produced_ in another. Hence we frequently observe fevers of different kinds to _follow_ every species of the weather that was mentioned in the last observation.

VIII. The excessive heat in Pennsylvania has sometimes proved fatal to persons who have been much exposed to it. Its morbid effects discover themselves by a difficulty of breathing, a general languor, and, in some instances, by a numbness and an immobility of the extremities. The excessive cold in Pennsylvania has more frequently proved fatal, but it has been chiefly to those persons who have sought a defence from it, by large draughts of spiritous liquors. Its operation in bringing on sleepiness previous to death, is well known. On the 5th of February, 1788, many people were affected by the cold. It produced a violent pain in the head; and, in one instance, a sickness at the stomach, and a vomiting appeared to be the consequence of it. I have frequently observed that a greater number of old people die, during the continuance of extreme cold and warm weather, than in the same number of days in moderate weather.

IX. May and June are usually the healthiest months in the year.

X. The influence of the winds upon health, depends very much upon the nature of the country over which they pass. Winds which pass over mill-dams and marshes in August and September, generally carry with them the seeds of fevers.

XI. The country in the neighbourhood of Philadelphia was formerly more sickly than the central parts of the city, after the 20th of August. Since the year 1793, the reverse of this has been the case.

XII. The night-air is always unwholesome from the 20th of August, especially during the passive state of the system in _sleep_. The frequent and sudden changes of the air from heat to cold render it unsafe to sleep with open windows, during the autumnal months.

XIII. Valetudinarians always enjoy the most health in Pennsylvania in the summer and winter months. The spring, in a particular manner, is very unfavourable to them.

I shall conclude the account of the influence of the climate of Pennsylvania upon the human body, with the following observations.

1. The sensations of heat and cold are influenced so much by outward circumstances, that we often mistake the degrees of them by neglecting to use such conveniences as are calculated to obviate the effects of their excess. A native of Jamaica often complains less of the heat, and a native of Canada of the cold, in their respective countries, than they do under certain circumstances in Pennsylvania. Even a Pennsylvanian frequently complains less of the heat in Jamaica, and of the cold in Canada, than in his native state. The reason of this is plain. In countries where heat and cold are intense and regular, the inhabitants guard themselves, by accommodating their houses and dresses to each of them. The instability and short duration of excessive heat and cold in Pennsylvania, have unfortunately led its inhabitants, in many instances, to neglect adopting customs, which are used in hot and cold countries to guard against them. Where houses are built with a southern or south-western front exposure, and where other accommodations to the climate are observed in their construction, the disagreeable excesses of heat and cold are rendered much less perceptible in Pennsylvania. Perhaps the application of the principles of philosophy and taste to the construction of our houses, within the last thirty or forty years, may be another reason why some old people have supposed that the degrees of heat and cold are less in Pennsylvania than they were in former years.

2. The variable nature of the climate of Pennsylvania does not render it _necessarily_ unhealthy. Doctor Huxham has taught us, that the healthiest seasons in Great-Britain have often been accompanied by the most variable weather. His words upon this subject convey a reason for the fact. "When the constitutions of the year are frequently changing, so that by the _contrast_ a sort of _equilibrium_ is kept up, and health with it; and that especially if persons are careful to guard themselves well against these sudden changes[36]." Perhaps no climate or country is unhealthy, where men acquire from experience, or tradition, the arts of accommodating themselves to it. The history of all the nations of the world, whether savage, barbarous, or civilized, previously to a mixture of their manners by an intercourse with strangers, seems to favour this opinion. The climate of China appears, in many particulars, to resemble that of Pennsylvania. The Chinese wear loose garments of different lengths, and increase or diminish the number of them, according to the frequent and sudden changes of their weather; hence they have very few acute diseases among them. Those inhabitants of Pennsylvania who have acquired the arts of conforming to the changes and extremes of our weather in dress, diet, and manners, escape most of those acute diseases which are occasioned by the sensible qualities of the air; and faithful inquiries and observations have proved, that they attain to as great ages as the same number of people in any part of the world.

[36] Observations on the Air and Epidemic Diseases, vol. I. p. 5.

AN ACCOUNT

OF THE

BILIOUS REMITTING FEVER,

AS IT APPEARED

_IN PHILADELPHIA_,

IN THE SUMMER AND AUTUMN OF THE YEAR 1780.

Before I proceed to describe this fever, it will be necessary to give a short account of the weather, and of the diseases which preceded its appearance.

The spring of 1780 was dry and cool. A catarrh appeared among children between one year, and seven years of age. It was accompanied by a defluxion from the eyes and nose, and by a cough and dyspn[oe]a, resembling, in some instances, the cynanche trachealis, and in others a peripneumony. In some cases it was complicated with the symptoms of a bilious remitting, and intermitting fever. The exacerbations of this fever were always attended with dyspn[oe]a and cough. A few patients expectorated blood. Some had swellings behind their ears, and others were affected with small ulcers in the throat. I met with only one case of this fever in which the pulse indicated bleeding. The rest yielded in a few days to emetics, blisters, and the bark, assisted by the usual more simple remedies in such diseases.

An intermittent prevailed among adults in the month of May.

July and August were uncommonly warm. The mercury stood on the 6th of August at 94-1/2°, on the 15th of the same month at 95°, and for several days afterwards at 90°. Many labouring people perished during this month by the heat, and by drinking, not only cold water, but cold liquors of several kinds, while they were under the violent impressions of the heat.

The vomiting and purging prevailed universally, during these two warm months, among the children, and with uncommon degrees of mortality. Children from one year to eight and nine years old were likewise very generally affected by blotches and little boils, especially in their faces. An eruption on the skin, called by the common people the prickly heat, was very common at this time among persons of all ages. The winds during these months blew chiefly from the south, and south-west. Of course they passed over the land which lies between the city, and the conflux of the rivers Delaware and Schuylkill, the peculiar situation of which, at that time, has been already described.

The dock, and the streets of Philadelphia, supplied the winds at this season, likewise, with a portion of their unwholesome exhalations.

The muschetoes were uncommonly numerous during the autumn. A certain sign (says Dr. Lind) of an unwholesome atmosphere.

The remitting fever made its first appearance in July and August, but its symptoms were so mild, and its extent so confined, that it excited no apprehensions of its subsequent more general prevalence throughout the city.

On the 19th of August the air became suddenly very cool. Many hundred people in the city complained, the next day, of different degrees of indisposition, from a sense of lassitude, to a fever of the remitting type. This was the signal of the epidemic. The weather continued cool during the remaining part of the month, and during the whole month of September. From the exposure of the district of Southwark (which is often distinguished by the name of the _Hill_) to the south-west winds, the fever made its first appearance in that appendage of the city. Scarcely a family, and, in many families, scarcely a member of them, escaped it. From the Hill it gradually travelled along the second street from the Delaware, improperly called Front-street. For a while it was confined to this street only, after it entered the city, and hence it was called by some people the _Front-street fever_. It gradually spread through other parts of the city, but with very different degrees of violence. It prevailed but little in the Northern Liberties. It was scarcely known beyond Fourth-street from the Delaware. Intemperance in eating or drinking, riding in the sun or rain, watching, fatigue, or even a fright, but more frequently cold, all served to excite the seeds of this fever into action, where-ever they existed.

All ages and both sexes were affected by this fever. Seven of the practitioners of physic were confined by it nearly at the same time. The city, during the prevalence of the fever, was filled with an unusual number of strangers, many of whom, particularly the Friends (whose yearly meeting was held in the month of September), were affected by it. No other febrile disease was observed during this time in the city.

This fever generally came on with rigour, but seldom with a regular chilly fit, and often without any sensation of cold. In some persons it was introduced by a slight sore throat, and in others by a hoarseness which was mistaken for a common cold. A giddiness in the head was the forerunner of the disease in some people. This giddiness attacked so suddenly, as to produce, in several instances, a faintness, and even symptoms of apoplexy. It was remarkable, that all those persons who were affected in this violent manner, recovered in two or three days.

I met with one instance of this fever attacking with coma, and another with convulsions, and with many instances, in which it was introduced by a delirium.

The pains which accompanied this fever were exquisitely severe in the head, back, and limbs. The pains in the head were sometimes in the back parts of it, and at other times they occupied only the eyeballs. In some people, the pains were so acute in their backs and hips, that they could not lie in bed. In others, the pains affected the neck and arms, so as to produce in one instance a difficulty of moving the fingers of the right hand. They all complained more or less of a soreness in the seats of these pains, particularly when they occupied the head and eyeballs. A few complained of their flesh being sore to the touch, in every part of the body. From these circumstances, the disease was sometimes believed to be a rheumatism; but its more general name among all classes of people was, the _break-bone fever_.

I met with one case of pain in the back, and another of an acute ear-ach, both of which returned periodically every night, and without any fever.

A nausea universally, and in some instances a vomiting, accompanied by a disagreeable taste in the mouth, attended this fever. The bowels were, in most cases, regular, except where the disease fell with its whole force upon them, producing a dysentery.

The tongue was generally moist, and tinctured of a yellow colour.

The urine was high coloured, and in its usual quantity in fevers.

The skin was generally moist, especially where the disease terminated on the third or fourth day.

The pulse was quick and full, but never hard, in a single patient that came under my care, till the 28th of September.

It was remarkable, that little, and, in some instances, no thirst attended this fever.

A screatus, or constant hawking and spitting, attended in many cases through the whole disease, and was a favourable symptom.

There were generally remissions in this fever every morning, and sometimes in the evening. The exacerbations were more severe every other day, and two exacerbations were often observed in one day.

A rash often appeared on the third and fourth days, which proved favourable. This rash was accompanied, in some cases, by a burning in the palms of the hands and soles of the feet. Many people at this time, who were not confined to their beds, and some, who had no fever, had an efflorescence on their skins.

In several persons the force of the disease seemed to fall upon the face, producing swellings under the jaw and in the ears, which in some instances terminated in abscesses.

When the fever did not terminate on the third or fourth day, it frequently ran on to the eleventh, fourteenth, and even twentieth days, assuming in its progress, according to its duration, the usual symptoms of the typhus gravior, or mitior, of Doctor Cullen. In some cases, the discharge of a few spoons-full of blood from the nose accompanied a solution of the fever on the third or fourth day; while in others, a profuse hæmorrhage from the nose, mouth, and bowels, on the tenth and eleventh days, preceded a fatal issue of the disease.

Several cases came under my care, in which the fever was succeeded by a jaundice.

The disease terminated in some cases without sweating, or a sediment in the urine; nor did I observe such patients more disposed to relapse than others, provided they took a sufficient quantity of the bark.

About the beginning of October the weather became cool, accompanied by rain and an easterly wind. This cool and wet weather continued for four days. The mercury in the thermometer fell to 60°, and fires became agreeable. From this time the fever evidently declined, or was accompanied by inflammatory symptoms. On the 16th of October, I met with a case of inflammatory angina; and on the next day I visited a patient who had a complication of the bilious fever with a pleurisy, and whose blood discovered strong marks of the presence of the inflammatory diathesis. His stools were of a green and black colour. On the third day of his disease a rash appeared on his skin, and on the fourth, in consequence of a second bleeding, his fever terminated with the common symptoms of a crisis.

During the latter end of October, and the first weeks in November, the mercury in the thermometer fluctuated between 50° and 60°. Pleurisies and inflammatory diseases of all kinds now made their appearance. They were more numerous and more acute, than in this stage of the autumn, in former years. I met with one case of pleurisy in November, which did not yield to less than four plentiful bleedings.

I shall now add a short account of the METHOD I pursued in the treatment of this fever.

I generally began by giving a gentle vomit of tartar emetic. This medicine, if given while the fever was in its forming state, frequently produced an immediate cure; and if given after its formation, on the _first_ day, seldom failed of producing a crisis on the third or fourth day. The vomit always discharged more or less bile. If a nausea, or an ineffectual attempt to vomit continued after the exhibition of the tartar emetic, I gave a second dose of it with the happiest effects.