during June, until I reached Philadelphia, it fluctuated between 60° and 80°; the weather was on the whole fine, but frequently for a day or two together the air felt extremely raw and disagreeable. The changes in the state of the atmosphere were also sometimes very sudden. On the sixth day of June, when on my way to Frederic-town, after passing the Patowmac River, the most remarkable change of this nature took place which I ever witnessed. The morning had been oppressively hot; the thermometer at 81°, and the wind S. S. W. About one o’clock in the afternoon, a black cloud appeared in the horizon, and a tremendous gust came on, accompanied by thunder and lightning; several large trees were torn up by the roots by the wind; hailstones, about three times the size of an ordinary pea, fell for a few minutes, and afterwards a torrent of rain came pouring down, nearly as if a water-spout had broken over head. Just before the gust came on, I had suspended my thermometer from a window with a northern aspect, when it stood at 81°; but on looking at it at the end of twenty-three minutes, by which time the gust was completely over, I found it down to 59°, a change of 22°. A north-west wind now set in, the evening was most delightful, and the thermometer again rose to 65°. In Pennsylvania the thermometer has been known to vary fifty degrees in the space of twenty-six hours. The climate of the middle and southern states is extremely variable; the seasons of two succeeding years are seldom alike; and it scarcely ever happens that a month passes over without very great vicissitudes in the weather taking place. Doctor Rittenhouse remarked, that whilst he resided in Pennsylvania, he discovered nightly frosts in every month of the year excepting July, and even in that month, during which the heat is always greater than at any other time of the year, a cold day or two sometimes intervene, when a fire is found very agreeable. The climate of the state of New York is very similar to that of Pennsylvania, excepting that in the northern parts of that state, bordering upon Canada, the winters are always severe and long. The climate of New Jersey, Delaware, and the upper parts of Maryland, is also much the same with that of Pennsylvania; in the lower parts of Maryland the climate does not differ materially from that of Virginia to the eastward of the Blue Ridge, where it very rarely happens that the thermometer is as low as 6° above cipher.