Page:Notes on the State of Virginia (1802).djvu/118

108 between theſe two places, the latter being 38° 8′ 17″, which is 52′ 22″ north of the former. By cotemporary obſervations of between five and ſix weeks, the averaged, and almoſt unvaried difference of the height of mercury in the barometer, at thoſe two places, was. 784 of an inch, the atmoſphere at Monticello being ſo much the lighteſt, that is to ſay, about one-thirty-ſeventh of its whole weight. It ſhould be obſerved, however, that the hill of Monticello is of 500 feet perpendicular height above the river which waſhes its baſe. This poſition being nearly central between our northern and ſouthern boundaries, and between the bay and Alleghaney, may be conſidered as furniſhing the beſt average of the temperature of our climate. Williamſburg is much too near the ſouth-eaſtern corner to give a fair idea of our general temperature.

But a more remarkable difference is in the winds which prevail in the different parts of the country. The following table exhibits a comparative view of the winds prevailing at Williamſburgh, and at Monticello. It is formed by reducing nine months obſervations at Monticello to four principal points, to wit, the north-eaſt, ſouth-eaſt, ſouth-weſt, and north-weſt; theſe points being perpendicular to, or parallel with our coaſt, mountains, and rivers: and by reducing in like manner, an equal number of obſervations, to wit, 421 from the preceding table of winds at Williamſburgh, taking them proportionably from every point.