^{page 476 note *} It may be proper to repeat, that, in all the combinations of the differential thermometer, the divisions of the scale are made to correspond with the thousand parts of the interval between freezing and boiling water.

^{page 494 note *} In this stage of the inquiry, it may be proper to notice a singular observation, Which I have not yet had an opportunity of repeating. An æthrioscope exposed to the free air, on a platform projecting towards the north, from the window of my experimental room in Queen Street, stood a few weeks since, in a clear frosty day, at about 25 degrees; but, on the approach of evening, a light wind having suddenly turned to the opposite point of the compass, the atmosphere became at once obscured by a body of very thick and dark smoke: the liquor, contrary to all expectation, immediately rose more than 10 degrees, and remained stationary till the dense mass again disapersed. This stratum of fuliginous matter would no doubt absorb the frigorific impressions showered from the sky; yet being precipitated by its collected weight, it would bring down intense coldness from the superior regions, and therefore dart new impressions, rendered the more powerful from the proximity of their source.

^{page 495 note *} Αἴθρῳ ϰαι ϰαμάτῳ δεδμημένον ἦγεν ἐς οἶϰον. Odyss. Lib. xiv. 318.

^{page 495 note †} Ὡς δ᾿ ὅτε ταρφειαὶ νιφάδες Διὸς ἐκποτέονται,

Ψυχραι ὑπαὶ ῥιῶῆς αἰθρηγενέος Βορέαο. Iliad. Lib. xix. 357–8.

Καὶ Βορέης αἰθπηγενέτης, μέγα κῦμα κυλινδων. Odyss. Lib. v. 296.

^{page 495 note ‡} Δυσαύλων πάγων ἄιθϱια

Κὰι δυσομβϱα φευγειν βέλη. Antigone, 357.

^{page 495 note ║} Θερμοτεροι γαρ δη εσι το ὑδωρ τῆς τε αίθριας και τῆς δροσɤ. Euterpe.