Wind blows from the Mountains all round the Island: and still a Sea-Breeze over the Mountains: to the Low-Lands, none, 604. (In Jamaica likewise the Wind blows off the Island _every way_ at once, so that no Ship can any where come in by Night, or go out but early in the Morning, before the Sea-Breeze sets in. See Abr. Phil. Tr. Vol. 3, P. 548.) _Mountain Air rushes down in a continual Current to every Part of the Coast, the Stream descending incessantly throu’ the Night: while heavy cold Air descends to the Mountain Tops_, 604. With a _West_ Wind below there is an _East Scud above_, 605. _Mountains_ +cloudy+, _low Lands_ +sunny+. 606. In +all+ _the River-Courses of Jamaica, there is a sensible Current of Air. Rain never comes without some Wind: and the Showers almost invariably follow the very Meanders of the larger Rivers_, 608. Rain always cools: the Thermometer falling, after a Shower, from 6 to 8 Degrees, 610. (And Iron rusts least in rainy Weather: [the Air being then +driest+,] descending from the _upper_ Regions. Abr. Ph. Tr. V. 3, P. 546.)” It is said also that “in Jamaica the Clouds gather, and _shape_ according to the Mountains: so that _old Seamen_ will tell you each _Island_ towards Evening, by the _Shape_ of the Cloud _over_ it.” The Sea-Breeze, being counterpoised by _Descent_ of the _etherial Air_, produces a +calm+. The same Author likewise says, that “the Clouds begin to gather about 2 or 3 o’Clock in the Afternoon _at the Mountains_, and do not _embody_ first in the Air, and after settle there, but _settle_ first and _embody_ there: the rest of the Sky being clear till _Sun-set_. So that they do not pass _near_ the Earth in a _Body_, and only _stop_ where they meet with Parts of the Earth elevated _above the rest_; but +precipitate+ _from a very great Height_, and in Particles of an _exceeding rarified Nature_; _so as not to obscure the Air or Sky at all_: that great Variety of beautiful Colours in the Canopy of Heaven being raised to a much greater Distance [he means Height] in Jamaica than it is here.” Abr. Ph. Tr. V. 3, P. 557. (Prognostics of Weather, at certain Periods of the Moon, are mentioned by Captain Langford. Lowthorp’s Abr. Phil. Trans. Vol. 2, Page 105.) [68] The Depression of a _Torrent_ of Air in the Form of an hyperbolic Solid, _contracting_ as it _descends_ to the Earth, in Proportion as its _Density_ encreases; may furnish a Hint towards the Solution of a Difficulty how to account for the Augmentation of vesiculous Vapours into large solid Drops, frequent during _Summer_-Showers. [69] Mons. Saussure’s valuable “Essais sur L’Hygrometrie,” throw new Light on the Doctrine of Rarefaction and Condensation not unfavourable to the Hypothesis here advanced. Page 260. [70] Ice, when exposed to marine acid Air, is dissolved by it, as fast as if it touched a red hot Iron. See Cavallo’s Treatise on Air, Page 727. Also Priestley’s Experiments and Observations, Vol. 1, Page 148.