[66] In the same Manner that Curls and Streams of Air _descended_ into the Bason over the rising _Steam_, and interrupted the Regularity of _its_ Elevation; in the _larger_ Towns, during Winter (_the Weather being moderate_) the Pressure of Air on all Sides, from without, produces a constant Breeze towards the Center of the Town: as may be discovered, not only by the Smoke in its Deviation from the Perpendicular, as it issues from the Chimneys; but by all who are inclined to make the Trial; for, on leaving the Town, they will _meet_ the Breeze. In calm Weather, during Summer, the contrary Event happens: but more particularly in _hot_ Climates. For the Country being hotter than the Town; a _Depression_ of the Atmosphere takes Place, and scatters the Smoke on all Sides round the Town. The Cities in Italy, and other hot Climates, on Account of the Buildings, and _desirable_ Narrowness of the Streets, form _one_ contiguous _Shelter_, _Arbor_, or grand _Parasol_: For which Reason, the Nobility leave the Country, and reside in the Towns during Summer: there finding a Coolness and Refreshment unknown on the _scorching_ Plains. A _Reception_ and _Dispersion_ of Air takes Place; _as will presently be mentioned_. The same ocular Proof and Process in the Evaporation of Steam, accounts at once, for a curious Phenomenon constantly observable on all Waters; viz. _a narrow_ +smooth+ _irregular Surface of considerable Length, nearly in the Direction of the Wind, yet unaffected by it_: all which is probably nothing more than _rising_ Volumes of _elastic invisible_ Steam; _resisting_ the _two_ nearest _descending Waves_ of +air+; and preventing them from approaching the _Surface_ of Water, over which the Steam is compressed; and _there_ producing a _temporary_ +calm+. [67] Phil. Trans. for 1777, Page 470. Thibet in Lat. 31, _cold_ with Snow and Frost. See Ullòa’s Voyage to South-America, Book 6, Chapter 7; where he describes the snowy Mountains, under the Equator. As the Weather, near the Equinoctial, is more regular, its Changes closely following those of the Moon; and also the Winds and Hurricanes more violent; the Truth of the foregoing Theory will receive the strongest Confirmation by tracing the Effects of +depressing torrents of air+, in the Island of Jamaica, extracted from the Author already mentioned. “The cool Vapour _rushes_ from the Mountains towards the hot dry Air, which hovers over the Savannahs or Vallies. The Rain falls heaviest in the Mountains. Vol. 3, Page 600. The _Land-Wind_ after Rain, proceeds from that Quarter whence the Rain has fallen _heaviest_; and seems to _rush_ from above. In Spain and North-America, the Wind _rushes down_. Page 601. When the _Land_ is _most_ heated, the Sea-Breeze blows almost _all_ Night. Page 602. The Barometer subsides from 1 Inch to 1½ _at_ the full Moon, or just _after_ it.