[57] The Doctrine of smokey Chimnies distinctly treated of under the Article smoke, in the Encyclopædia Britannica, may receive some Improvement, from Circumstances which ascertain the sudden Descent, Elevation, and quick Depression of Columns or rather Torrents of Air, viz. by widening the Tubes, and covering their Tops.
[58]It is thought more candid, and will to many be more satisfactory; to make occasional References to different Authors who have treated distinctly on a Subject, and leave the Reader to draw his own Conclusions by applying to their express Words;—than, either to insert abundant Quotations; or weave their Thoughts into the Texture of the Work: which must encrease its Bulk, without producing any Thing either new or instructive.
[59]Once, particularly, in the Month of January, at Lausanne: Farenheit’s Thermometer at 7 only: the Country covered with Snow; and a North Wind beating violently on the Lake, which continued liquid without Ice: owing, perhaps, in Part, to subterranean Heat, and Exhalations.
[60]The Depression and Reverberation of the Wind near Rivers, and its Descent from Mountains, a Point to be discussed, may furnish a Hint and Reason, why Rain falls more in one Place, than in another not far distant: and why in the same Place it falls in different Quantities, at different Heights, irregularly.
[61] Cavallo’s Treatise on Air, Page 446.—
[62] 442.—
[63] 441.—
[64] 442.
[65] It is light in Consequence of its Warmth, when compared with the cooler condensed Air above it.
[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.