Every allowance being made for other causes, I am still of the opinion that the difference in the climates of the Ohio and lake regions of country, is to be attributed chiefly to the prevalence of different currents of air. The southern current rarely, if ever, reaches the northern lakes, and the northern, until lately, never reached the Gulf of Mexico. But as the country is cleared of its native forests, we may reasonably conclude this cold current of air will prevail more and more, until we shall have snow enough for sleighs, at least two months in every winter; the summers will be shorter, the extremes of heat and cold will be greater than at present, and those clouds which formerly obscured the sun almost continually during the summer months, will be chased away, and with them the pale cheek, the sallow hue, the oppression at the breast, and the difficulty of respiration, the headache, and the thousand ills which many of the first emigrants have experienced in our climate. We shall probably then have fewer diseases, and more acute ones. The storms will probably be fewer, more severe, and not continue as long as at present. There are still further views which might be taken of this subject, but they are left to abler pens and future observations. Thus I have endeavoured to give my opinion on a subject of some interest to the present, as well as future generations; in doing which, I have not sought for flowers which might have been gathered by stepping out of my path, but the _fruit_ rather of my own observation and experience: I have not wandered through the fields of imagination, invoking the poetic muse, but addressed myself chiefly "To him who soars on golden wing, Guiding his fiery-wheeled throne, The cherub contemplation." ART. XIII. _On a singular Disruption of the Ground, apparently by Frost, in Letters from_ EDWARD HITCHCOCK, A.M. _Principal of Deerfield Academy_. (With a Plate.) _To the Editor of the American Journal of Science, &c._ SIR, I have lately examined a singular disruption in the earth, discovered a few days since in the northerly part of an extensive meadow in this town, about ten rods from Deerfield river. The soil on the spot is alluvial, consisting of a dry, rich, vegetable mould, with a large intermixture of sand; and the field, elevated 14 feet above the bed of the river, is annually mowed. A valley encircles the ruptured spot on the east, south, and west, only five feet lower, yet so marshy and soft, as to render draining necessary to make it passable; and immediately back of this valley, on the south, rises a hill 100 feet high, at whose foot are several springs. North of the rupture, also, between it and the river, is a gradual descent of three feet: indeed, the ground slopes from it on every side except the northwest.