To know whether the Air is hazy, tho’ the Sun continues shining.
The Method taken for that Purpose was by placing the Hand so as to cover his Disk or Body, and then observe the Glory blazing round him; which may, in general, be seen to issue in great Abundance, in Rays of a golden Colour: occasioned by a Haziness or Vapour which pervades the lower Regions of the Air, most frequently in the hottest and calmest Weather, and in the hottest Climates. The Accumulation of these Vapours, before they are formed into Clouds, are often so great as to intercept the Sun’s Rays, or dye them the Colour of Blood: an Appearance frequent in Virginia, and also throughout the torrid Zone.
In the Campania of Rome, for Instance, the Italians have a peculiar Name for such Kind of Weather, when the Sun is neither visible nor invisible: Il Sole si vede, e’ non si vede.
By Degrees the Hand is to be removed so as just to have a Glance of the Sun’s Limb. And it frequently happens that the Air is exceedingly hazy; tho’ not a Cloud appears above the Horizon.
[14] Esse in Imaginibus quâpropter Causa videtur Cernendi, neque posse sine his Res ulla videri.
Lucretius de Rerum Natura. L. 4. V. 238.
[15] Notwithstanding what has been said; this, to the great and to the sordid Vulgar, woud still appear a solitary, helpless, and deplorable Situation. But such are not captivated with the golden Lines of Epictetus, (Chap. 13. Line 3. see Mrs. Carter’s Translation.)
“ΠΑΝΤΑ ΘΕΩΝ μεστα και ΔΑΙΜΟΝΩΝ·—Βλεπων τον ΗΛΙΟΝ και Σεληνην, και Ἀστρα, και ΓΗΣ απολαυων και ΘΑΛΑΣΣΗΣ, ἐρημος εστιν ου μαλλον ἠ και ἀβοηθητος·” Nor are they practically influenced by the better Words of a much finer Writer: “The Earth is full,” &c. &c. And “If I take the Wings of the Morning,” &c. &c.
[16] There being, at first, no Clouds, as usual, to occupy the Place of the lowest Stratum.
[17] It has been said that the apparent Height from the Balloon to the Ground was 7 Miles, viz. 4 to the Summit of the Clouds, and 3 below: and the barometric Height was about a Mile and half, viz. 2332 Yards, a Calculation of which will be given.
If then we divide that Height or Distance into 2 such Parts, that the greater shall be to the less as 4 to 3; we obtain the Length of each Part; i. e. the barometric Height from the Balloon to the Summit of the Clouds, and thence to the Earth; which is done thus: