1 determined by observations of the heat which prevails in deep wells and springs. The heat of the atmosphere, is derived from the heat, which takes place at the surface of the earth. In passing through the atmosphere, the solar rays do not communicate any heat to the particles of air. The rays must first fall upon the earth, be stopped, and collected, before they produce their effect: And no greater heat can ever be communicated to the atmosphere, than was first communicated to the surface of the earth. Hence we find the temperature of those wells and springs, which are so far beneath the surface of the earth, as not to be much affected by the heat in summer, or by the cold in winter, is the same as the mean temperature of that climate; or the mean heat of the atmosphere, in that place. The temperature of the water in the deep wells in this place, is exactly the same as the mean heat of the atmosphere. I have repeatedly examined the temperature of the water in a well near the State House, by estimation forty five feet in depth, and I have always found the heat to be 43 and a half degrees, without any variation in summer or winter.* * On a Journey from the University at Newhaven in Connecticut, to Burlington upon Onion river, I made the following observations upon the temperatu re of the wells; which may serve to show in what manner the heat decre afes, as we advance towards the north, in a country but little cultivated. ANOTHER View of the climate may be taken from the common operations of nature, the vegetable and animal productions. The times when the trees and plants put forth their buds, leaves, flowers and fruit, or when the different seeds are planted, spring up, are in blossom, produce their fruit, and are gathered in ; when the birds of passage, or other migratory animals,, make their approach or departure. Observations upon such phenomena, are among the best observations we can ever have, to ascertain the relative temperatures of different climates. Referring those which relate to the migration of animals, to the description of the birds, one or two small tables will serve to give us a view of the times, when different vegetables produce their fruit, in this part of the continent. A view of the Climate, taken from the state of Vegetation in the Trees and Shrubs. Trees and Shrubs. Flowers. Maturity. Elder, 15 Gooseberry, April Currant, April April 16 6 April 16 May 9 july 20 May 1 July 1 Raspberry, April 6 April 17 May Strawberry, April 20 April 20 May 6 June 15 Wild Cherry, 4 June 28 1 August 12 Apple Tree, 12 August 18 Wild Plumb, April 20 April 28 May A view of the Climate, taken from the fruits of THE frosts commonly cease about the beginning of June, and come on again between the first and the middle of September. When they first come, they appear not on the hills, or highest parts of the trees, but in the low and wet lands, and on the lowest parts of the trees. When a fog lies along the low lands adjoining to a river, when the winds are high, and when the lands are but partly or newly cleared, the frosts are retarded or prevented; and do not appear so soon, or so great, as in clear, low, and wet places. These circumstances seem to explain the reason why the frosts are first seen not on the high, but on the low lands. The dews and vapours are the most dense and abundant, in those places; much more so than they are at higher altitudes, or upon the hills. The first effects of the frost are not sufficient to freeze the leaves of the trees, or other vegetables. The cold at first avails only to effect the congelation of the dew and vapour; as these are chiefly to be found in the low and moist lands, and not higher than the lowest limbs of the trees, these are the places where the first effects of the frosts appear. A high wind serves to prevent these effects, by carrying off the dew and vapours; and a fog detains the heat in amazing quantities, and prevents its flowing off from the surface of the earth, either so rapidly, or in such quantities, as to occasion a frost. In those places where the earth is not covered with snow, the frost penetrates several feet below the surface. In the winter of 1789 there was but little snow at Rutland; and the sur face of the earth was frozen almost the whole winter. On March the 19th the ground was frozen to the depth of three feet and eight in ches. The ice in the lakes and stagnant waters, is generally frozen in the course of the winter, about thirty inches thick; in the rivers and streams it is about twenty four; and commonly goes off the last week in March. THE severest cold of our winters never kills any of our young trees, and seldom freezes any of our young cattle, although they are not housed during the winter. Nor is the cold so affecting to the human body, as the extremes, and sudden changes from heat to cold, on the sea coasts. From the time that the winter first sets in, until it breaks up, we have generally a settled steady cold; for the most part without any thaw, and with but a few days in which the snow melts at all. During this period we become accustomed to the weather, and every thing in our feeling, and clothing is adapted to a steady and severe cold. Such a steady, equal temperature, is far more comfortable than those great and sudden changes which take place, where the extremes of heat and cold are frequently succeeding each other. THE temperature of the American climate is so different in different parts of the same state, and often in the same latitude, that it cannot be well understood, but by viewing it in its variations through the different parts of the northern continent. The following table is designed to exhibit such a comparative view. 5 years 44 41° 2 February 54 43 44, 59 48 April 70 5.3 59, May 75 65 June 79 July 81 POMONO 66, 7 70 74, 9 73 799 76. 78, 6 72 November 53 49 50, December 51 40 45, 2222796 96 96 Mean Heat. Mean Heat. Mean Heat. Mean Heat. Mean Heat. Mean Heat. Mean 51 Temperature of Climate at sundry places in N.America, from Thermometrical Observations. Virginia. Pennsylvania. Massachusetts. Vermont. University of Canada. Rutland. Vermont, Hudson's Bay. lat. 37 16' lat. 44° 27'. obs. 1 year obser. 5 years obst years obs. 5 years obs.1 years obs. 15 years obs. years obs. years obs. 1738-42.1753 and 4. 1772-7. 1748 and 9. 1784-8. 17.89. 1803-8. 1743 and 41768 and 9. 18 10 6 Greatest Heat. 101 93 98 Lining. Brooke. Phil. Trans. Phil. Tra. Vol. 45 1759. P. 58 Page 341. Williams. D.C.Sanders. Gautier Hist. Acad. Phil. Trans. Royal Scie 1770. P. 137. 11745. P. 194-1 Wales. |