But as this Oeconomy, fo neceffary in its Contitution, might be frequently incommoded by Rains, the Author of Nature has furnished Birds with an Expedient that renders their Feathers as impenetrable to the Water, as they are, by their Structure, to the Air. + All Birds have a Bag filled with Oil, and fhaped like a Nipple, the Situation of which is at the Extremity of their Body. This Nipple has feveral little Apertures, and when the Bird finds her Feathers dry, foiled, difcontinued by Gaps, or ready to be moistened, fhe preffes this Nipple with her Bill, and forces out an Oil, or fat Humour, referved in the Glands; and then drawing her Bill over the greatest Part of her Feathers fucceffively, oils and dreffes them, gives them a Luftre, and fills up all the Vacancies with this viscous Matter; after which, the Water only flides over the Bird, and finds all the Avenues to her Body perfectly clofed. Our Poultry, who live under a Covert, have a lefs Quantity of this Liquor than Birds who inhabit the open Air; for which Reafon a Hen, when fhe is wet, makes a ridiculous Figure: On the contrary, Swans, Geefe, Ducks, Moorhens, and all Birds deftined to live on the Water, have their Feathers preffed with Oil from their very Birth. Their Magazine contains a Provifion of this Fluid, proportionable to the Neceffity of its Confumption, which is continually returning; their very Flesh contracts the Flavour of it, and every one may observe that the Care of oiling their Feathers, is their conftant Em~ ployment.

+Willoughby's Orthinolog. lib. I.

The Wings.

If there is fo much Wifdom in the Structure of the Feathers, there is no lefs in the Play of the Wings and Tail, in order to traverse the Air. Nothing can be better placed than the Wings; they form, on each Side, two Levers which keep the Body in a juft Poife; at the fame Time, they perform the Function of Oars, which, by bearing on the Element that refifts them, advance the Body in a contrary Direction.

The Tail.

The Tail is a Counterpoise to the Head and Neck, and serves the Bird inftead of a Rudder, whilft he rows with his Wings; but this Rudder is not only inftrumental in preferving the Equilibrium of the Flight; it likewife enables the Bird to rife, defcend, and turn where he pleases; for as foon as the Tail is directed to one Point, the Head turns to the oppofite Quarter.

Chevalier. Though I don't comprehend how Birds perform their Flight, I am of Opinion, it is not impracticable for Man to imitate them; and the Birds inftruct him in the Method he ought to obferve.

Prior. 'Tis certain, that we have the Principle of Motion in our Legs and Arms; we likewife have, in the Feathers of Birds, and in our Linen Cloth and Oil, Materials of a feeming Fitness to form Wings, capable both of ftriking and impelling the Air, without being penetrated by it. The Birds fupply us with a Model of the Action, and, at first View, it seems to be an Invention naturally prefented to us, and which a fmall Effort, or a few Reflexions; would fuffice to make us acquire in Perfection; but I believe God, in Confequence of his providential Care of Mankind, has oppofed an infuperable

Impediment in the Way; fo that this Attempt, which has been frequently repeated, hath always proved unfuccefsful. The Art of Flying would be the greatest Calamity that could happen to Society.

Chevalier. On the contrary, Sir, I should think this Invention would fave us abundance of Labour. We should be fooner acquainted with what we are defirous of knowing; and if we had once found out a fmall Machine, could foon build a larger. We fhould not only traverse the Air ourfelves, but might likewife convey Cargoes of Merchandize through that Element. By this means Commerce.

Prior. You have a charming Penetration, Chevalier, and are the best in the World at gueffing the Advantages we might receive from this Invention; but thefe Advantages would not countervail the Disorders that would be introduced.

Count. This is certain, that were Men capaсараble of flying, no Avenue could be inacceffible to Vengeance and inordinate Defires. The Habitations of Mankind would be fo many Theatres of Murder and Robbery. What Precautions could we take against an Enemy, who would be capacitated to furprise us both by Day and Night? How fhould we preferve our Money, our Furniture, and Fruits from the Avidity of a Sett of Plunderers, furnished with good Arms to force open our Houses, and as good Wings to carry off their Booty, and elude our Purfuit? This Sort of Trade would be the Refuge of every indigent and impious Perfon.

Prior. I may add to this, that the Art we are now mentioning would intirely change the Face of Nature; we should be compelled to abandon our Cities, and the Country, and to bury our

felves in fubterraneous Caves, or imitate Eagles and other Birds of Prey; we should retire, like them, to inacceffible Rocks and craggy Mountains, from whence we should, from time to time, fally down upon the Fruits and Animals that ac commodate our Neceffities; and, from the Plain, we should immediately foar up to our Dens aud Charnel Rooms.

Countefs. Ah! Gentlemen, you make me tremble at your Art of Flying; and I beftow, beforehand, my Imprecations on the Perfon, who fhall attempt to make it practicable. Let me hear no more of Dens and Charnel Rooms. Do you fee, Chevalier, what you expofe us to with your Inventions?

Count. Make your felf eafy on this Head. We need not be under any Apprehenfions about the Art of Flying, which indeed is an abfolute Impoffibility; Nature herself has formed an Obstacle against it, that is, in fome Measure, made invincible, by the exceeding Difproportion between the Weight of the Air, and an human Body. The hollow Machine that one muft imagine capable of fuftaining the Body of a Man, and placing it in an equal Ballance with the Air, would be fo immoderately large and cumbersome, that learned Men have judged the Management and Use of it to be altogether impracticable, and as much forbidden to Man as the perpetual Motion.

Countess. Are you difpofed, Gentlemen, to refume the Subject of Birds to-morrow?

Count. There is no want of Variety. The Dif ficulty lies in confining ourselves to a due Limitation. What fhall be the Articles of our Entertainment?

Prior Let each chufe what is most agreeable to his Tafte, and ferve it up as a Country Collati

on.

Chevalier. If the Prior pleases to be my Security, I will acquit myself like the rest.

Countefs. For my part, Gentlemen, I promise you before-hand a Bird found in no Place but America; 'tis the least and most beautiful of all Birds, and should it not be fufficient for you, I will make you amends with an Ostrich.

DIALOGUE