page 20 note * This feature is well set forth by DrMarcet, , F.R.S., in his recent book Southern and Swiss Health Resorts, p. 262Google Scholar; except that he speaks of the return S. West current as being immediately above the cloud, in place of, as it is throughout all the summer season, separated from it by a thickness of full 5000 feet of a gradually decreasing strength of N. East wind, the same in direction as what prevails both below, and in, the cloud level, but differing hygrometrically therefrom exceedingly, in being extraordinarily dry. This important physical peculiarity is afterwards, however, fully acknowledged by Dr Marcet at pp. 296 to 306 of his useful book. For he there sets forth in a fuller and more serious manner that the N. East cloud level is never so low as 1200 feet, but nearer to 3000 feet high; and by its shade moderates both the temperature, the radiation and the moisture of the country below it. But at his Guajara station, 7090 feet high and therefore altogether above that N. East cloud level, he found there was still a prevailing tendency of the wind to blow from the North East, but accompanied by a terrific dryness, amountiug on one occasion to 30° 5 depression of the wet, below the dry, bulb thermometer. Even on the higher central Peak, at 10,700 feet elevation, he says that “ the S. West current, bringing back moisture from between the tropics,” was only beginning to be felt; and the traveller would have to ascend several thousand feet higher still, if he could, to reach the full force and volume of that important stratum, at that season. All which exactly agrees with my own experience, described in Teneriffe, , an Astronomer's Experiment, in 1856Google Scholar.
