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that many times they fly in numberless troops, or swarms, and for sundry days together before they fall, are seen over those places in great high clouds, such as coming nearer, are of extension enough to obscure the day, and hinder the light of the sun. From which, together with divers other such relations, he concludes that 'tis not altogether improbable they should proceed from the moon. Thus likewise he supposeth the swallows, cuckoos, nightingales, with divers other fowl, which are with us only half the year, to fly up thither, when they go from us. Amongst which kind, there is a wild-swan in the East Indies, which at certain seasons of the year do constantly take their flight thither. Now this bird being of great strength, able to continue for a long flight, as also going usually in flocks, like our wild-geese; he supposeth that many of them together might be taught to carry the weight of a man; especially if an engine were so contrived (as he thinks it might) that each of them should bear an equal share in the burden. So that by this means 'tis easily conceivable, how once every year a man might finish such a voyage; going along with these birds at the beginning of winter, and again returning with them at the spring.

And here, one that had a strong fancy, were better able to set forth the great benefit and pleasure to be had by such a journey. And that whether you consider the strangeness of the persons, language, arts, policy, religion of those inhabitants, together with the new traffic that might be brought thence. In brief, do but consider the pleasure and profit of those later discoveries in America, and we must needs conclude this to be inconceivably beyond it.

Another of Dr. Wilkins's books is a series of amusing exercises in what he calls Mixed Mathematics, first printed while he was at Oxford, and republished in 1680. He entitled it "Mathematical Magick," or the wonders that may be performed by mechanical geometry. Its first part, called “ Archimedes," illustrates powers of the lever, wheel, pulley, wedge, and screw, and one chapter in it is said in its title to be "concerning the infinite strength of wheels, pulleys, and screws; that it is possible by the multitude of these, to pull up any oak by the roots with a hair, lift it up with a straw, or blow it up with one's breath; or to perform the greatest labour with the least power. The second part, called "Dædalus," abounds in suggestion of mechanical motions. Here are two :

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Of a Sailing Chariot, that may without Horses be driven on the Land by the Wind, as Ships are on the Sea.

The force of wind in the motion of sails may be applied also to the driving of a chariot, by which a man may sail on the land, as well as by a ship on the water. The labour of horses or other beasts, which are usually applied to this purpose, being artificially supplied by the strength of winds.

That such chariots are commonly used in the champion plains of China, is frequently affirmed by divers credible authors. Boterus mentions that they have been tried also in Spain, though with what success he doth not specify. But above all other experiments to this purpose, that sailing chariot at Sceveling in Holland, is more eminently remarkable. It was made by the direction of Stephinus, and

1 "De incremento Urbium," 1. 1. c. 10. (The references are given in the margin of his book by Dr. Wilkins.)

is celebrated by many authors. Walchius affirms it to be of so great a swiftness for its motion, and yet of so great a capacity for its burden: "Ut in medio freto secundis ventis commissas naves, velocitate multis parasangis post se relinquat, et paucarum horarum spatio, viginti aut triginta milliaria Germanica continuo cursu emetiatur, concreditosque sibi plus minus vectores sex aut decem, in petitum locum transferat, facillimo illius ad clavum qui sedet nutu, quaqua versum minimo labore velis commissum, mirabile hoc continenti currus navigium dirigentis." That it did far exceed the speed of any ship, though we should suppose it to be carried in the open sea with never so prosperous wind: and that in some few hours' space it would convey six or seven persons, twenty or thirty German miles, and all this with very little labour of him that sitteth at the stern, who may easily guide the course of it as he pleaseth.

That eminent inquisitive man Peireskius, having travelled to Sceveling for the sight and experience of this chariot, would frequently after with much wonder mention the extreme swiftness of its motion. 3" Commemorare solebat stuporem quo correptus fuerat cum vento translatus citatissimo non persentiscere tamen, nempe tam citus erat quam ventus." Though the wind were in itself very swift and strong, yet to passengers in this chariot it would not be at all discernible, because they did go with an equal swiftness to the wind itself: men that ran before it seeming to go backwards, things which seem at a great distance being presently overtaken and left behind. In two hours' space it would pass from Sceveling to Putten, which are distant from one another above fourteen horaria milliaria, (saith the same author), that is, more than two and forty miles. Grotius is very copious and elegant in the celebration of this invention, and the author of it in divers epigrams. "Ventivolam Tiphys deduxit in æquora navim, Jupiter in stellas, æthereamque domum. In terrestre solum virtus Stevnia, nam nec Tiphy tuum fuerat, nec Jovis istud opus."4

And in another place

"Imposuit plaustro vectantem carbasa malum
An potius navi subdidit ille rotas ?
Scandit aquas navis, currus ruit aëre prono,
Et merito dicas, hic volat, illa natat."5

These relations did at the first seem unto me, (and perhaps they will so to others) somewhat strange and incredible. But upon farther enquiry, I have heard them frequently attested from the particular eyesight and experience of such eminent persons, whose names I dare not cite in a business of this nature, which in those parts is so very common and little observed.

I have not met with any author who doth treat particularly concerning the manner of framing this chariot, though

24 Fabularum Decas," Fab. 9.

3" Pet. Gassendus vita Peireskii," 1. 2.

"Grotii Poemata," Ep. 19. This quotation and the next are from the second book of Epigrams in the collected poems of Grotius, that book consisting entirely of twenty-two epigrams on the sailing chariots made for Prince Maurice of Nassau, Captain-General of the United States of Holland, by Simon Stevin of Bruges, who had been his teacher in mathematics, and who was made by him superintendent of the dykes. He died in 1635, and was the inventor of the sailing chariots, used afterwards for some time upon the Dutch plains and frozen canals. This epigram says: Tiphys brought down the sailing ship into the seas, Jove placed it in the skies, Stevin on earth; that was not your work, Tiphys, nor Jove's.

5 Ep 5. Here two lines at the close of the epigram are added to two from the middle: Did he put on a chariot a mast bearing sa ls, or add wheels to a ship? The ship climbs the water, the chariot runs swiftly with air, and you may rightly say this flies, that swims.

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A SAILING CHARIOT.

four wheels of an equal bigness, with two sails like those in a ship; there being some contrivance to turn and steer it, by moving a rudder which is placed beyond the two hindmost wheels; and for the stopping of it, this must be done, either by letting down the sail, or turning it from the wind.

Of this kind they have frequently in Holland other little vessels for one or two persons to go upon the ice, having sledges instead of wheels, being driven with a sail; the bodies of them like little boats, that if the ice should break, they might yet safely carry a man upon the water, where the sail would be still useful for the motion of it.

I have often thought that it would be worth the experiment to enquire, whether or no such a sailing chariot might not be more conveniently framed with moveable sails, whose force may be impressed from their motion, equivalent to those in a wind-mill. Their foremost wheels (as in other chariots) for the greater facility, being somewhat lower than the other, answerable to this figure.

In which the sails are so contrived, that the wind from any coast will have a force upon them to turn them about; and the motion of these sails must needs turn the wheels, and consequently carry on the chariot itself to any place (though fully against the wind) whither it shall be directed.

The chief doubt will be, whether in such a contrivance, every little ruggedness or unevenness of the ground, will not 1 Epig. 20, 21.

A CHARIOT ON THE WINDMILL PRINCIPLE.

delightful, or better husbandry, than to make use of the wind (which costs nothing, and eats nothing) instead of horses? This being very easy to be effected by those, the convenience of whose habitations doth accommodate them for such experiments.

Concerning the Possibility of Framing an Ark for Submarine Navigations. The Difficulties and Conveniences of such a Contrivance.

It will not be altogether impertinent unto the discourse of these gradient Automata,2 to mention what Mersennus doth so largely and pleasantly descant upon, concerning the making of a ship, wherein men may safely swim under the

water.

That such a contrivance is feasible, and may be effected, is beyond all question, because it hath been already experimented here in England by Cornelius Drebel; 3 but how to improve it unto public use and advantage, so as to be serviceable for remote voyages, the carrying of any considerable number of men, with provisions and commodities, would be of such excellent use, as may deserve some further enquiry.

2 "Tract. de Magnetis Proprietatibus."

3 Cornelius van Drebbel, born at Alcmaer, in 1572, died in London 1631. He improved telescopes and microscopes, invented a thermometer, speculated on the possibility of producing rain and cold by machines. He is said to have invented scarlet dyeing, and given the secret to his daughter, whose husband, Cuffler, first practised the art.

Concerning which there are two things chiefly consider

able:

The many Difficulties with their Remedies.
The Great Conveniences.

1. The difficulties are generally reducible to these three heads.

1. The letting out, or receiving in anything, as there shall be occasion, without the admission of water. If it have not such a convenience, these kind of voyages must needs be very dangerous and uncomfortable, both by reason of many noisome, offensive things, which should be thrust out, and many other needful things which should be received in. Now herein will consist the difficulty, how to contrive the opening of this vessel so, that anything may be put in or out, and yet the water not rush into it with much violence, as it doth usually in the leak of a ship.

In which case, this may be a proper remedy; let there be certain leather bags made of several bignesses, which for the matter of them should be both tractable for the use and managing of them, and strong to keep out the water; for the figure of them, being long and open at both ends. Answerable to these, let there be divers windows, or open places in the frame of the ship, round the sides of which one end of these bags may be fixed, the other end coming within the ship, being to open and shut as a purse. Now if we suppose this bag thus fastened, to be tied close about towards the window, then anything that is to be sent out, may be safely put into that end within the ship, which being again close shut, and the other end loosened, the thing may be safely sent out without the admission of any water.

So again, when anything is to be taken in, it must be first received into that part of the bag towards the window, which being (after the thing is within it) close tied about, the other end may then be safely opened. It is easy to conceive, how by this means any thing or person may be sent out, or received in, as there shall be occasion; how the water, which will perhaps by degrees leak into several parts, may be emptied out again, with divers the like advantages. Though if there should be any leak at the bottom of this vessel, yet very little water would get in, because no air could get out.

2. The second difficulty in such an ark will be the motion or fixing of it according to occasion: the directing of it to several places, as the voyage shall be designed, without which, it would be very useless, if it were to remain only in one place, or were to remove only blindfold, without any certain direction: and the contrivance of this may seem very difficult, because these submarine navigators will want the usual advantages of winds and tides for motion, and the sight of the heavens for direction.

But these difficulties may be thus remedied; as for the progressive motion of it, this may be effected by the help of several oars, which in the outward ends of them, shall be like the fins of a fish to contract and dilate. The passage where they are admitted into the ship being tied about with such leather bags (as were mentioned before) to keep out the water. It will not be convenient perhaps that the motion in these voyages should be very swift, because of those observations and discoveries to be made at the bottom of the sea, which in a little space may abundantly recompense the slowness of its progress.

If this ark be so ballast as to be of equal weight with the like magnitude of water, it will then be easily moveable in any part of it.

As for the ascent of it, this may be easily contrived, if there be some great weight at the bottom of the ship (being part of its ballast) which by some cord within may be loosened from it as this weight is let lower, so will the ship ascend

from it (if need be) to the very surface of the water; and again, as it is pulled close to the ship, so will it descend.

For direction of this ark, the Mariners' Needle may be useful in respect of the latitude of places; and the course of this ship being more regular than others, by reason it is not subject to tempests or unequal winds, may more certainly guide them in judging of the longitude of places.

3. But the greatest difficulty of all will be this: how the air will be supplied for respiration: how constant fires may be kept in it for light and the dressing of food; how those vicissitudes of rarefaction and condensation may be maintained.

It is observed, that a barrel or cap, whose cavity will contain eight cubical feet of air, will not serve a urinator' or diver for respiration, above one quarter of an hour; the breath which is often sucked in and out, being so corrupted by the mixture of vapours, that nature rejects it as unserviceable. Now in an hour a man will need at least three hundred and sixty respirations, betwixt every one of which there shall be ten second minutes, and consequently a great change and supply of air will be necessary for many persons, and any long space.

And so likewise for the keeping of fire; a close vessel containing ten cubical feet of air, will not suffer a wax candle of an ounce to burn in it above an hour before it be suffocated; though this proportion (saith Mersennus) doth not equally increase for several lights, because four flames of an equal magnitude will be kept alive the space of sixteen second minutes, though one of these flames alone in the same vessel will not last above thirty-five, or at most thirty seconds; which may be easily tried in large glass bottles, having wax candles lighted in them, and with their mouths inverted in water.

For the resolution of this difficulty, though I will not say, that a man may, by custom (which in other things doth produce such strange incredible effects) be enabled to live in the open water, as the fishes do, the inspiration and expiration of water serving instead of air, this being usual with many fishes that have lungs; yet it is certain, that long use and custom may strengthen men against many such inconveniences of this kind, which to unexperienced persons may prove very hazardous: and so it will not perhaps be unto these so necessary, to have the air for breathing so pure and defecated, as is required for others.

But further, there are in this case these three things considerable.

1. That the vessel itself should be of a large capacity, that as the air in it is corrupted in one part, so it may be purified and renewed in the other; or if the mere refrigeration of the air would fit it for breathing, this might be somewhat helped with bellows, which would cool it by motion.

2. It is not altogether improbable, that the lamps or fires in the middle of it, like the reflected beams in the first region, rarefying the air, and the circumambient coldness towards the sides of the vessel, like the second region, cooling and condensing of it, would make such a vicissitude and change of air, as might fit it for all its proper uses.

3. Or if neither of these conjectures will help, yet Mersennus2 tells us in another place, that there is in France one Barrieus a diver, who hath lately found out another art, whereby a man might easily continue under water for six hours together; and whereas ten cubical feet of air will not

1 Urinator, Latin, from "urinari," to plunge under water. A diver. The word was used also by John Ray, a famous hotanist who was contemporary with John Wilkins.

2" Harmon.," 1. 4., prop. 6., Monit. 5.

serve another diver to breathe in for half an hour, he by the help of a cavity, not above one or two foot at most, will have breath enough for six hours, and a lanthorn scarce above the usual size to keep a candle burning as long as a man please, which (if it be true, and were commonly known) might be a sufficient help against this greatest difficulty.

As for the many advantages and conveniences of such a contrivance, it is not easy to recite them.

1. 'Tis private; a man may thus go to any coast of the world invisibly, without being discovered or prevented in his journey.

2. "Tis safe; from the uncertainty of tides, and the violence of tempests, which do never move the sea above five or six paces deep. From pirates and robbers which do so infest other voyages: from ice and great frosts, which do so much endanger the passages towards the poles.

3. It may be of very great advantage against a navy of enemies, who by this means may be undermined in the water, and blown up.

4. It may be of special use for the relief of any place that is besieged by water; to convey unto them invisible supplies; and so likewise for the surprisal of any place that is accessible by water.

5. It may be of unspeakable benefit for submarine experiments and discoveries; as, the several proportions of swiftness betwixt the ascent of a bladder, cork, or any other light substance, in comparison to the descent of stones or lead. The deep caverns, and subterraneous passages, where the seawater, in the course of its circulation, doth vent itself into other places, and the like. The nature and kinds of fishes, the several arts of catching them, by alluring them with lights, by placing divers nets about the sides of this vessel, shooting the greater sort of them with guns, which may be put out of the ship by the help of such bags as were mentioned before, with divers the like artifices and treacheries, which may be more successfully practised by such who live so familiarly together. These fish may serve not only for food, but for fuel likewise, in respect of that oil which may be extracted from them; the way of dressing meat by lamps, being in many respects the most convenient for such a voyage.

The many fresh springs that may probably be met with in the bottom of the sea, will serve for the supply of drink, and other occasions.

But above all, the discovery of submarine treasures is more especially considerable; not only in regard of what hath been drowned by wrecks, but the several precious things that grow there; as pearl, coral, mines; with innumerable other things of great value, which may be much more easily found out, and fetched up by the help of this, than by any other usual way of the urinators.

To which purpose, this great vessel may have some lesser cabins tied about it, at various distances; wherein several persons, as scouts, may be lodged for the taking of observations, according as the admiral shall direct them; some of them being frequently sent up to the surface of the water, as there shall be occasion.

All kinds of arts and manufactures may be exercised in this vessel. The observations made by it, may be both written, and (if need were) printed here likewise. Several colonies may thus inhabit, having their children born, and bred up without the knowledge of land, who could not choose but be amazed with strange conceits upon the discovery of this upper world.

I am not able to judge what other advantages there may be suggested, or whether experiment would fully answer to these notional conjectures. But, however, because the inven

tion did unto me seem ingenious and new, being not impertinent to the present enquiry, therefore I thought it might be worth the mentioning.

Dr. Wilkins's house was a museum of curiosities, and his foremost place among scientific inquirers caused him to be a member of the first Council of the Royal Society, a society which Cowley honoured

as

So virtuous and so noble a design,

So human for its use, for knowledge so divine—

which was incorporated by letters patent, dated the 22nd of April, 1663. It was founded, as its letters patent said, to advance "philosophical studies, especially those which endeavour by solid experiments either to reform or improve philosophy." Soon afterwards Dr. Wilkins became Dean of Ripon, and in November, 1668, he was consecrated Bishop of Chester. That was four years before his death.

It was in April, 1668, that Robert Boyle left Oxford for London. Among his Oxford friends,, besides Dr. Wilkins, had been Dr. John Wallis and Dr. Seth Ward, the Savilian Professors of Geometry and Astronomy; Christopher Wren, then a Fellow of All Souls; and other men of science, among whom Boyle worked in his own way. He invented the air-pump at this time. The first conception of the air-pump is to be ascribed to Otto Guericke, a magistrate of Magdeburg, who constructed a rude. machine about the year 1654, and showed experiRobert Boyle was at work in the same direction a little later. He had in his house as an assistant an ingenious man, Robert Hooke, who had been recommended to him by Dr. Thomas Willis, the physician. In 1658 or 1659 Hooke perfected Boyle's instrument, and produced an air-pump far surpassing the machine of Otto Guericke. Robert Hooke was made first Curator of Experiments to the Royal Society, and in 1664 its Professor of Mechanics.

ments.

Robert Boyle, born in 1626, the year of Bacon's death, was the fourteenth child of Richard Boyle, Earl of Cork, who, with convenient opportunities, had gained large estates and an Earldom by taking advantage of the political condition of Ireland. In 1643, when the Earl died, Robert was a youth of seventeen, who had been educated at Eton and Geneva. With estate enough bequeathed to him, he followed the bent of his mind, and joined a deep religious feeling to a keen study of nature by way of experiment. Boyle published many little books that set forth the results of his inquiries or maintained the union of science with religion. He never named God without a reverent pause; refused to take orders with assurance of high church promotion; declined also the Presidency of the Royal Society because, although a Churchman, he would not be He bound by test and oaths on taking office. declined the Provostship of Eton, and several times refused a peerage. He remained unmarried until his death, in 1691, his elder sister, Lady Ranelagh, being his lifelong friend and housekeeper. He survived her only a week.

In 1665 Boyle published some "Occasional Re

flections upon several subjects: whereto is premised a Discourse about such kind of Thoughts." He had

ROBERT BOYLE.

From the Frontispiece to his "Motives and Incentives to the Love of God," 1670.

written them early in life, but here is one upon the occasion of the Coronation of Charles II. :—

AN OCCASIONAL REFLECTION

Upon a Letter (received in April, 1662), containing an Account of what passed on the King's Coronation Day, in a little Country Town.

I need not, Pyrocles, after what we have been reading, tell you that the writer of this letter thinks that both in what he has said of the king, and what he has done to solemnize his coronation, he has behaved himself rarely well. For I doubt not, but you easily discern by his way of writing, that he is highly satisfied with his performances, and expects that he shall, if not be thanked by the king, at least be mentioned in the news-book. But it will, I fear, be requisite to tell you that this honest man is not alone of his mind; for being his landlord's bailiff, he is esteemed at that rate by his neighbours, and looked upon as a man very considerable in his parish; and is perhaps thought to have a right to pity most of those that do not admire what he has now been doing. And yet, you and I, who pretend not to be courtiers, can, in his rural encomiums, and in his ill-contrived way of honouring his prince, easily discover so much that might have been mended, and so much that might be laughed at, that, if the king, according to his wonted graciousness, vouchsafe this action his smiles, it must not be in consideration of the suitableness of the performances to the occasion, but, partly as they proceed from a hearty, though ill-expressed, loyalty and love, and partly as they afford him a subject of merriment. And not only the nice critics, who have seen those magnificent solemnities, and heard the eloquent panegyrics, wherewith the principal cities and assemblies in the nation have thought they did but part of what they should; and not only those assiduous courtiers who, by the honour of a nearer access, have opportunities (denied to others) of discovering those particularities that may best give a high veneration for a great person and a great prince, to those that are qualified

to discern and relish such things; not only these, I say, will have a quite other opinion of the rural praises, and antique ceremonies that were so well liked a hundred miles from London; but this countryman himself, if he were admitted to the Court and bred a while there, would in time see so great a distance betwixt what he has done, and what a person better bred might have done, that he could not remember without blushes, what he now looks upon with triumph.

And now I must on this occasion confess to you, Pyrocles, that I have (on other rises') several times been revolving in my thoughts, what the angels think of those praises and descriptions of God that men devise (for I intend not here to speak of those the Scripture suggests) and wherein we are most applauded by others, and do oftentimes perchance applaud ourselves. For those celestial courtiers (if I may so call them) have several advantages to assist them in the celebration of our common Master, which we poor mortals want. For first, they are free from those selfish and inordinate affections that too often hinder us either from discerning the excellency of divers of God's attributes and ways, or from duly acknowledging it. They have no sins to keep them from descrying the justness of what He does; they have no ingratitude to oppose the fuller resentments of His goodness; and they are not tempted not to discern and adore His wisdom, for fear they should appear culpable for repining at His dispensations. And, indeed, their longevity allowing them the full prospect from end to end of those intricate transactions of Providence of which short-lived mortals do commonly see but a part; they are questionless far more satisfied with the incomparably better contrivances they discern in the management of human affairs, than we are with the conduct of plots of the most skilfully written plays and romances. Besides, those happy spirits, of whom the Scripture tells us that they stand before God and that they continually see His face, have by that privilege, the blessed opportunities of discovering in the Deity they contemplate and serve, many excellences which even they could never but by experience have formed any thoughts of; and they see in one another's solemn adorations and praises, a way of honouring the object of them so much transcending the utmost of what we here aim at, that their homages to their Creator may well be supposed of a far nobler kind than ours. And lastly, when I consider how much less unworthy thoughts and expressions touching things divine the same person may have, when come to his full maturity of age and parts, and whilst he was but a child in both; and when I consider, how much more advantageous conceptions of the wisdom displayed in the universe, and particularly in the contrivance of a human body, one that is a true philosopher and a skilful anatomist may have, in comparison of a man illiterate and unacquainted with dissections: When, I say, I consider these things, and compare the dim twilight of human intellects in this life, with that clear and radiant light which the Scripture ascribes to angels, I cannot but think, that, having to the privilege of a much nearer access than is allowed us to contemplate God's perfections, the advantage of having incomparably more illuminated intellects to apprehend them with, they must frame otherguess conceptions of the Divine attributes, and glorify the possessor at an otherguess rate, than is allowed to those, whose understandings are so dim, and whose residence is so remote from that blessed place, where the perfections they would extol are most displayed.

Assisted by these and the like advantages, Pyrocles, those happy spirits may well frame notions and employ expressions in honour of their Maker, so far transcending ours that,

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1 Rises, heights.

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