Washington, March 29th, 1821. F To the Editors of the New-York Medical Repository. GENTLEMEN, I have taken the liberty of enclosing to you for publication, an abstract of Meteorological observations at the Military posts in the United States, during the third quarter of the last year. When comparing it with those made during the two first quarters, several important inferences are suggested; and we are encouraged in the belief of being able to trace, with some degree of accuracy, both the causes and effects of the general and regular changes of winds, temperature, and weather, during the course of the year, and for a succession of years. More detailed and continued observations may enable us to ascertain how far these are modified by peculiarities of position, and other local circumstances; and what effect each, or the combination of both, may have upon our diseases. Thus, there are some diseases which prevail at certain points, whenever the mean temperature of the season is above or below a certain degree. These, it would appear, depend upon a combination of general and local causes; for these points are scattered over a great extent of country, and their number bears a pretty direct proportion to the magnitude of the general atmospheric changes; while the intermediate healthy spots, often in the vicinity of the former, prove the necessity of local agents to produce the effect. Many extensive epidemics are neither arrested, nor materially affected by localities; while a great proportion of our diseases proceed from causes obviously confined to the places in which they originate. Practical results may be expected from a series of observations, which should enable us in any degree to approximate to the ratio, which these causes bear to each other: the one may be altogether beyond our control, but the other admits of material modification. The following remarks may facilitate a comparative view of the reports for the several quarters of the year. The mean temperature for July was 77.17; for August, 78.85; for September, 71.05; and for the quarter 75.03. In July the course of the winds was in the following proportion S.W. 8-S.51-S.E.5-W.3--N.E.21-N.W.2-E.2being 19 from the southern, and 7 from the northern quarter. In August, S.W.9-S.4-S.E.4-W.4.N.W.31-N.E.21E.-N.1; being 17 from the southern, and 7 from the northern quarter. In September, S.W.71-N.E.5-N.W.41 S.31-S.E.25-W.21-N.21-E.21; being 13, from the southern, and 12 from the northern quarter. Out of 27 places of observation, the prevailing weather was fair in July, at 20, varying at 6, and equally divided at 1. In August, fair at 25, and varying at 2. In September, fair at 25, varying at 1, and cloudy at 1. The proportion in July, was 181 fair, 4 cloudy, and 8 rains; in August, 19 fair, 5 cloudy and 7 rain; in September, almost 20 fair, 5 cloudy, and 5 rain, during the quarter 57 fair, 14 cloudy, and 20 rain. The greatest proportion of fair weather was in September, the least in January. Comparing the western with the eastern posts, in about the same latitude, the difference of temperature is less than in the former quarter. The mean temperature at St Peter's in July at 2 P.M. was 2o above that at Sackett's Harbour. In August, 31; in September they were equal. At Prairie du Chein the mean temperature, at the same time, was, in July, 7.56 above that in Boston Harbour; in August, 12.48; in September, nearly equal. At Council Bluffs, the mean temperature was, in July, 5.80 above that at Fort Trumbull, in Connecticut in August, 9.77; in September, 6.70. At Council Bluffs also, the mean temperature in July was one degree above that at New-Orleans: in Au : gust, 0°.84'; in September, 5°.69 below. During the first quarter, the prevailing wind was from the north-west; during the second, from the south-east; and during the third, from the south-west. Respectfully Your Ob't. Serv't. Surg. Gen. U.S.A. Note. The following posts were not included in the former reports, and therefore their latitude and longitude are now given, viz. Niagara, lat. 43° 14′, long. 79° 6', Detroit, lat.42o 30, long. 820 58'. Newport, R. I. lat. 41° 25′, long. 71°19. FortSevern, lat.39",long. 76°43′. Norfolk,lat.37°21', long. 76° 42'. Bay of St. Louis, lat. 30° 17', long. 89° 17'. |