Note 45 — Chapter XXX

It will be found, that, on comparing the

two

Calculations in Section 52, Note

Note [18]

,

corrected

; the circular

Distance

from the Eye, above the Clouds, was 102 Miles, 1 Quarter, 320 Yards: while

that

above the Earth, seen from the same elevated Situation, (supposing the Day to have been

clear

for such a View,) was 102 Miles, 1 Quarter, 307 Yards: whose Difference is only 13 Yards: that is, the

Distance

above the Clouds to the

nebulous

Horizon, was

rather

more extensive, than

that

above the Earth to the

terrestrial

Horizon.

It may not, to some Readers, be deemed either unentertaining, or foreign to the Subject; if the Distance of the Prospect from the Balloon at its greatest barometric Altitude, viz. 2332 Yards, or a Mile and Half within 33 Yards, be compared with the Distance which may be seen from the Summit of the principal Mountains in different Parts of the Globe.

1. Cotopàzy, a Mountain in the Province of Quito, in America, and under the equinoctial Line, is said by Ullòa (Vol. 1. Page 422) to be 3126 Toizes or Fathom, i. e. 6252 Yards, or 3 Miles and a Half and 92 Yards in Height.

2. White Mountain, called by the French Mount Blanc, near Geneva, is considered by Sir G. Shuckburgh (Phil. Trans. Vol. 67, Part 2d, Page 598, for the Year 1777) as the highest Land in Europe, Asia, or Africa (known to Europeans) and calculated by him at 5220 Yards, or 3 Miles within 60 Yards above the Level of the Mediterranean Sea.

Mons. Bourit just returned from his last Tour, see his “Description de Glacieres” in 1773, makes the White Mountain but 5102 Yards in Height, (which is 30 Yards lower than Teneriffe) including the 410 Yards for the Level of the Lake of Geneva above the Mediterranean.

3. The Peak of Teneriffe in the Canary Islands, which, in approaching towards it, Authors agree, may be seen at the Distance of 120 Miles at Sea, if the Weather is clear; (Modern History, Vol. 14th, Page 451;) and, in returning from it, is discoverable at the Distance of 150 Miles, according to Glas’s History of the Canaries (Page 234);—has been estimated by Dr. Heberden in Madeira (Guide to the Lakes, Page 187) at 5132 Yards, or 3 Miles within 148 Yards.

Glas remarks farther, that in sailing from Teneriffe, the Peak, at the Distance of 150 Miles is very little darker than the azure Sky, on Account of the great Quantity of Vapour intercepted between the Eye and the Mountain: and not because it ceased to be an Object too small for the Sight; or was in Fact, below the Horizon, and only raised by Refraction of the Vapour.

With Respect to the Peak of St. George, situated in the Island called Pico, one of the Azòres; the Writer of this Account asserts, from the Mouth of an able and experienced Officer in his em some Weeks off those Islands; that the latter has frequently observed the Peak, at the Distance of 120 Miles, and coud then distinguish a third Part of its Height down the Mountain. Section 126, Note [37]), see also [46] below.

4. Etna is 3877 Yards above the Mediterranean: (according to Brydone’s Tour throu’ Sicily and Malta, Vol. 1. Page 211) or 2 Miles and 357 Yards.

5. Blue Ridge, the highest Mountain in the Island of Jamaica, is, according to Dr. Clark, who measured it in November last, 3080 Yards, or 1 Mile and three Quarters, above the Level of the Ocean.

The distance to be seen is considered as terminating the Radius of a Circle, whose Center is the eye of the Observer, on each Mountain.

Height of the Mountains. distance to be seen from them in Miles.

Cotopàzy 3 Miles and a Half and 92 Yards, (for the Process, see Section 52, Note [18] 167​1⁄2 and 405 Yards.

White Mountain 3 Miles within 60 Yards. 153​1⁄4 and 13 Yards.

Peak of Teneriffe 3 Miles within 148 Yards. 152 within 72 Yards.

Mount Etna 2 Miles and 357 Yards. 132 and 127 Yards.

Blue Ridge 1 Mile and 3 Quarters. 117​3⁄4 and 30 Yards.

Balloon 1 Mile and half within 33 Yards. 102​1⁄4 and 307

As it is well known that Objects of the greatest Magnitude appear but as blue air at even a less Distance than 100 Miles; to which add the Difficulty of Journies, and Ascent to the Summit of these astonishing Mounds of Earth; and all this for the Sake, not of a complete down prospect, subject to a perpetual Variety, but merely an imperfect Side-View: the pleasure and ease of attaining still more stupendous Heights at any Place and Time, by Means of the balloon, are strikingly in Favor of that Invention. And, notwithstanding the confessed Merit of Dr. Black’s Project with the Farciminàlis of a Calf, and Mr. Cavallo’s Soap Bubbles with inflammable Air; (see his History of Aerostation, Page 34;) if the Emperor had been alive who offered a Reward for the Invention of a NEW PLEASURE; the first Prize had been due to the Brothers Montgolfier, and a second to the Brothers Roberts.