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of the most agreeable and temperate states in the Union. The season of frost and snow seldom exceeds three months; the winter commencing from the 1st to the 15th of December, and terminating from the 1st to the 15th of March. The heat of summer is seldom oppressive, except in low situations. In all the hilly parts the air is healthy; but near the sea-coast the temperature of winter is severe, varying in the months of January and February from fourteen to twentyeight degrees. The warm wind from the south and south-east brings on a sudden thaw, which instantly changes to frost when it shifts to the north-east and north-west. Such changes also take place in summer, and the difference of temperature between the afternoon and morning is often from twenty to thirty degrees, or even more after storms of rain and thunder. In the elevated parts the temperature is more regular. It is described by an accurate observer, Dr Rush, as a compound of all other climates. "In spring it has the moisture of Britain; in summer, the heat of Africa; the temperature of Italy in June; the sky of Egypt in autumn; in winter the cold and snow of Norway, and ice of Holland; the tempests of the West Indies in every season, and the monthly variable winds and weather of Great Britain."* The most agreeable
* According to the calculation of Baron de Humboldt, the mean annual temperature of Philadelphia, in latitude 50° 56,' is 12° 7' of the centigrade thermometer. Of winter, 1° 1'; of spring, 11° 7'; of summer, 24° 0'; of autumn, 13° 4'; of the coldest month, 0° 4'; of the warmest, 29° 0'. (Nova Genera et Species Plantarum Ahxandri de Humboldt, prolegomena.)
months are April, May, the 1st half of June, September, and part of October. The birds of passage begin to return about the middle of March. Cherries are ripe by the 25th of May; and wheat is commonly reaped before the middle of July.
Earthquakes.—A slight shock was felt at Philadelphia on the 5th of September 17^2, which extended to Boston and Montreal in Canada; another more considerable, which lasted half a minute, was felt in the month of November 173? •
Rivers.—The Susquehannah river rises in the state of New York, from the lakes Otsego and Otego, and runs across the state of Pennsylvania, to its outlet at the head of the Chesapeak bay, where it is more than a mile across. In its course it receives several important streams. The Tioga river, which runs eastwardly from the Alleghany mountains, joins it at Tioga Point, in latitude 41" 5?', three miles south of the boundary line. The western branch of the Susquehannah rises near the Connemagh branch of the Alleghany river, passes through the whole range of Alleghany mountains, and unites with the eastern at Sunbury, in latitude 41°, from which it is navigable for boats of 40 tons to the distance of 140 miles. The Juniata branch rises in the great chain of mountains, through which it winds a considerable distance; and after a course of 180 miles, unites its waters with the Susquehannah, about 15 miles above Harrisburg. The Juniata is navigable from Bedford to its mouth, a distance of 150 miles. On the east side this river receives the Swetara, and Conostoga, each running in a south-west course of about forty miles. The former is boatable to the distance of fifteen miles from its mouth. The Tioga branch is boatable fifty miles; but the Susquehannah itself is not navigable for more than twenty miles for ships of any burden, owing to the rapidity of the current, and numerous small rocks, that in many places reach the surface, or rise above it. If this river were navigable for boats, it would be of great utility, as the source of the east branch is in the Mohawk country, above 700 miles from the outlet in the Chesapeak.
Delaware River.—Ships of the line of 1200 tons ascend to Philadelphia, i HO miles from the sea, sloops of 90 tons to Trenton, 35 miles higher; boats of eight tons ascend 100 miles nearer its source, and Indian canoes 150; so that the whole length of boat navigation is 255 miles. The width of the river at Philadelphia is about a mile. The tide, which reaches as high as the falls of Trenton, flows at the rate of four miles an hour, and rises six feet. The Shuylkill branch descends from the north-west side of the Kittatiny, or Blue Mountains, and, after a south-easterly course of 120 miles, it unites with the Delaware, six miles below Philadelphia. The Leheigh, another branch, rising near Wilkesbarre, takes a course of 75 miles through the Blue Mountains, and is boatable 30 miles from its mouth at Easton.
The Alleghany river traverses the north-western parts of the state. Towards the north it crosses the line of boundary, passes through a part of the state of New York, and, re-entering Pennsylvania, holds on a course of 180 miles to its junction with the Monongahela, at Pittsburgh, where it is 400 yards in width. The current runs at the rate of two miles an hour, when the waters are at a moderate height, but at double this rate during the spring floods. On the 11th of November 1810 the waters rose thirty-seven feet above the common level, which was more than five feet higher than the flood of 1807-8, which was the highest that had been seen for twenty or thirty years.
The Monongahela river, * which waters the southwestern parts, issues from the Laurel mountains in Virginia, and runs first in a north-east, and afterwards in a north-west direction, to its junction with the Alleghany, at Pittsburg, where it is 450 yards in width, and sufficiently deep in the spring and fall for the passage of ships of 400 tons burden. The mean velocity of the current is about two miles an hour, and nearly double when the waters are at their greatest elevation. In May 1807 they rose at Brownsville forty feet above the common level, and carried away a number of grist mills; but this was an extraordinary circumstance. The mean height of water affords a boat navigation to Morgantown, a distance of 100 miles.
The counties of Huntingdon, Bedford, Centre, and Bellefonte, abound with springs, small rivers, and creeks. n
Minerals.—Iron ore is found in great quantity, in different parts of the counties of Mackearse, Potter,
* An Indian word, Meek mon aiaan getulatc, which signifies the stream of the falling in, or mouldering banks.
Armstrong, Huntingdon, Bellefonte, Centre, and Bedfort; iron sand, which gives iron equal in quality to the best Swedish, in Chester county, and on Hedgehill, in Buck's county; brown scaly iron ore, or brown oxide of iron, in a cavern at Messenburgh; also near Lancaster, and at Jenkington, in Montgomery county; copper ore, said to be of a rich quality, was lately discovered in Miflin township, in Columbia county; it is also found at Perkiomen; native copper in Adam's county; lead ore, in Perkiomen Creek, twenty-four miles from Philadelphia, which is said to yield 20 per cent, of this metal, and to contain a small portion of silver. This ore is also found in the Bald Eagle valley, and on the Conostoga creek, nine miles from Lancaster. Black lead, or plumbago, is found in Buck's county, in considerable quantity, t Basaltes, of a regular form, are found at Flourtown, thirteen miles from Philadelphia. Adatnan., line spar, in a rock of granite, at Chestnut hill, nine miles from the city of Philadelphia. Flint is common near Easton and Reading. Slate, of a good quality, is found on the banks of the Delaware, in Wayne county, seventy-five miles from Philadelphia, and at Northampton and other places near the Shuylkill, where it is employed to cover houses. Freestone and limestone is everywhere abundant; Jibrous limestone, of the colour of amber and semitransparent, in Cumberland valley, fifteen miles from Bedfort; marble, black and white, in Scheigh and Northampton counties; black, with white specks, at Aaronsburg, in Northumberland county; talc, or soapstone, of which