Meteorological observations and essays / By John Dalton.

  • John Dalton
Date:
1834
Catalogue details

Licence: Public Domain Mark

Credit: Meteorological observations and essays / By John Dalton. Source: Wellcome Collection.

    35/280 (page 9)
    and lowest observations each month, and the time they took place; as also the direction of the wind, and its strength, at the time: the direction we have usually referred to some one of § equidistant points of the compass, and the strength is de- noted by the figures 0, 1, 2, 3, and 4, respectively, the first marking a calm, or very gentle breeze, and the last a hurricane. The observations at London are only for 3 years, because the later ones could not be procured; those at Kendal and Keswick for 5 years, from 1788 to 1792, inclusive. To the end of these is added the mean monthly state of the barometer, found from the means of the 5 years, as also the mean upon the extremes, the former of which is corrected, on account of the variations of heat in the different months, by which the quicksilver in the barometer is contracted or dilated, though retaining the same weight.—We have also summed wp the spaces described by the quicksilver each month, noted the number of changes from ascent to descent, and the contrary, and found their amount for the year. By the mean state, applied to observations, is to be understood the sum of all the particular observations divided by their number. The upper part of the following tables, having no abbreviations, is sufficiently explicit; and in the under part, which contains the days in the several months on which the highest and lowest observations were taken, and the winds at those times, we have used H, for highest, L, for lowest, m, for morning, n, for noon, and nt, for night. N. B. Kendal bears N. 30° W. from London, distant nearly 226 English miles, measured on a great circle of the earth; Keswick bears N, 35° W. from Kendal, distant 22 English miles, measured on a great circle.