But it would be tedious to descend too far into Particulars, to reckon up the many Benefits of this noble Appendage of our Globe in many useful Engines[k]; in many of the Functions and Operations of Nature[l] in the Conveyance of Sounds; and a Thousand Things besides. And I shall but just mention the admirable use of our Atmosphere in ministring to the enlightening of the World, by its reflecting the Light of the heavenly Bodies to us[m]; and refracting the Sun-beams to our Eye, before it ever surmounteth our Horizon[n]; by which means the Day is protracted throughout the whole Globe; and the long and dismal Nights are shorten’d in the frigid Zones, and Day sooner approacheth them; yea the Sun itself riseth in Appearance (when really it is absent from them) to the great Comfort of those forlorn Places[o].
But passing by all these Things with only a bare mention, and wholly omitting others that might have been named, I shall only insist upon the excellent Use of this noble circumambient Companion of our Globe, in respect of two of its Meteors, the Winds, and the Clouds and Rain[p].
FOOTNOTES:
[a] Mundi pars est Aer, & quidem necessaria: Hic est enim qui cœlum terramque connectit, &c. Senec. Nat. Qu. l. 2. c. 4.
[] Ipse Aer nobiscum videt, nobiscum audit, nobiscum sonat; nihil enim eorum sine eo fieri potest, &c. Cic. de Nat. Deor. l. 2. c. 33.
[c] As the Air is of absolute Necessity to Animal Life, so it is necessary that it should be of a due Temperament or Consistence; not foul, by reason that suffocateth: not too rare and thin, because that sufficeth not; with Examples of each of which, I shall a little entertain the Reader. In one of Mr. Hawksbee’s Compressing Engines, I closely shut up a Sparrow without forcing any Air in; and in less than an Hour the Bird began to pant, and be concerned; and in less than an Hour and half to be sick, vomit, and more out of Breath; and in two Hours time was nearly expiring.
Another I put in and compressed the Air, but the Engine leaking, I frequently renewed the Compressure; by which means, (although the Bird panted a little after the first Hour,) yet after such frequent Compressures, and Immission of fresh Air, it was very little concerned, and taken out seemingly unhurt after three Hours.
After this I made two other Experiments in compressed Air, with the Weight of two Atmospheres injected, the Engine holding tight and well; the one with the Great Titmouse, the other with a Sparrow. For near an Hour they seemed but little concerned; but after that grew fainter, and in two Hours time sick, and in three Hours time died. Another thing I took notice of, was, that when the Birds were sick and very restless, I fancied they were somewhat relieved for a short space, with the Motion of the Air, caused by their fluttering and shaking their Wings, (a thing worth trying in the Diving-Bell). I shall leave the ingenious Reader to judge what the cause was of both the Birds living longer in compressed, than uncompressed Air; whether a less quantity of Air was not sooner fouled and rendred unfit for Respiration, than a greater.
From these Experiments two Things are manifested; one is, that Air, in some measure compressed, or rather heavy, is necessary to Animal Life: Of which by and by. The other, that fresh Air is also necessary: For pent up Air, when overcharged with the Vapours emitted our of the Animal’s Body, becomes unfit for Respiration. For which Reason, in the Diving-Bell, after some time of stay under Water, they are forced to come up and take in fresh Air, or by some such means recruit it. But the famous Cornelius Drebell contrived not only a Vessel to be rowed under Water, but also a Liquor to be carried in that Vessel, that would supply the want of fresh Air. The Vessel was made for King James I. It carried twelve Rowers, besides the Passengers. It was tried in the River of Thames; and one of the Persons that was in that submarine Navigation was then alive, and told it one, who related the Matter to our famous Founder, the Honourable, and most Ingenious Mr. Boyl. As to the Liquor, Mr. Boyl saith, he discovered by a Doctor of Physick, who married Drebell’s Daughter, that it was used from time to time when the Air in the submarine Boat was clogged by the Breath of the Company, and thereby made unfit for Respiration; at which time, by unstopping a Vessel full of this Liquor, he could speedily restore to the troubled Air such a proportion of vital Parts, as would make it again for a good while fit for Respiration. The Secret of this Liquor Drebell would never disclose to above one Person, who himself assured Mr. Boyl what it was. Vid. Boyl. Exp. Phys. Mech. of the Spring of the Air, Exp. 41. in the Digres. This Story I have related from Mr. Boyl, but at the same time much question whether the Virtues of the Liquor were so effectual as reported.