Papers on meteorology : relating especially to the climate of Britain, and to the variations of the barometer / by Luke Howard.

  • Howard, Luke, 1772-1864.
Date:
1850-1854
Catalogue details

Licence: Public Domain Mark

Credit: Papers on meteorology : relating especially to the climate of Britain, and to the variations of the barometer / by Luke Howard. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    cold, from the condensation effected by the approach of northern air to our own at- mosphere, previously charged with vapour to the full; and the dryness of 1829, with so much of cold, may have been the result of the great deposition of rain in the pre- vious season. The only rule, then, that prevails throughout, seems to be compensa- tion ; a wet year against a dry one, &c., and so of whole runs of seasons; and we must examine the winds for the cause. This I have done in my paper before the Royal Society alluded to above; but the subject, complicated as it is with the moon’s intricate orbit, and her varying influence on the currents that sweep these islands, is much too extended for the compass of this paper*. We have to do, here, not so much with causes as with the effects they produce ; a knowledge of which must necessarily go before the other. I shall pro- ceed therefore at once, from the review of the rain and temperature of whole years, to an analysis of the distribution of these through the several months of the year; which will let us probably into the secret of the difference, under equal quantities of rain, of the warm from the cold side of the cycle ; as regards the most important of its effects, the fruitful or unfruitful character of our seasons. The full flexuous line in fig. 2. (Plate V.) presents the monthly rain, in its total amounts under each month, for the nine years 1824 to 1882, or warm period; the dotted curve, the same for the nine years 1833 to 1841, or cold period of the cycle. I shall compare these with the temperature in another figure ; the present object is to show the remarkably different distribution of the like quantity of rain, in each. The warm period, then, shows December barely dry, its rain being three-tenths of an inch below the mean betwixt the driest and wettest months, which is at 19’59 inches. January, February and March are in the extreme of dryness. In April of this period, the rain suddenly mounts up to a point full three inches above the mean, and descends again three and a half inches below it, to make us a fine May. The months of June and July, though high in the scale of rain, have the advantage (the former considerably) in dryness of those of like denomination in the cold period. But in August and Sep- tember we see the case reversed; the amounts of rain in the warm exceeding (by about five inches in each) those of the cold period. October is wet in both nearly to the same degree; and by the by, I may here observe, that the rains in this month fall mostly by night; verifying a remark I heard many years since from a friend, that “there are always twenty fine days in October.” dVovember, though wet, is drier on the warm side by a quantity exceeding two and a half inches on the cycle: of De- cember we have treated as regards this side—to turn now to the other. [* See the papers referred to page 33, note; also page 41.] H