probable error in printing three different decimal figures thirty times every month) we must conclude that the fluctuations of the barometer at London and Malvern are very nearly simultaneous and equal, and, if so, of course in all places intervening.[1]
3. Vapour.—All those important meteorological phenomena, rain, cloud, mist, dew, &c. are primarily dependent upon the condition of the vaporous atmosphere which on every side surrounds us, and the health and feelings of individuals are very often materially influenced thereby; it is therefore requisite, in any estimate or comparison of climates, that the changes it is daily undergoing, should be ascertained and recorded. The hygrometer enables us to do this, particularly the one now well known as Daniell's hygrometer
In the Meteorological Tables, published by the Royal Society, there is a column including the dew-point every morning at nine a. m.; and I have made similar observations at the same hour at Malvern. The results are stated in the following table.
- ↑ The following remarks will not materially invalidate the above general conclusion; they tend, however, to shew that, occasionally, a little time is required in the passing of the great atmospheric oscillations over places one hundred miles from each other, and their apex of ascent and depression are not always quite equal at that distance.
On the morning of the 16th of January, both barometers had fallen to the minimum of the month. but the instrument at Malvern was for about two or three hours 1-10th inch below that in London; at this period, in Malvern, very heavy rain fell—whilst in London, the weather was overcast, light rain, light wind—at three p.m. on the same day, the barometers coincided.
On the 7th of March the minimum occurred—at Malvern at nine a. m.—in London at three p. m.; at the former place were very heavy showers and light wind—at the latter, lightly overcast with brisk wind.
