The history of the Royal-Society of London for the improving of natural knowledge by Tho. Sprat.
Sprat, Thomas, 1635-1713., Cowley, Abraham, 1618-1667. To the Royal Society.
Page  [unnumbered]Page  233

EXPERIMENTS Of the Recoiling of GUNS By the Lord BROVNCKER.

WHen I was commanded by this Society,*to make some Experiments of the Recoiling of Guns: In order to the discovery of the cause thereof, I caused this Engine that lyes here before you to be prepared, and with it (assisted by some of the most eminent of this So∣ciety) I had divers shots made in the Court of this Colledge, near the length thereof from the mark, with a full charge (about a fourpenny weight) of Powder; But without any other success, then that there was no∣thing Regular in that way, which was by laying it upon a heavy table, unto which it was sometimes fastned with Screws at all the four places R, L, V, B, sometimes on∣ly at R or L, having wheels affixed at L and V or R and B, that it might the more easily recoil.

This uncertainty I did then conceive might arise from one or more of these three causes, viz.

  • 1. The violent trembling motion of the Gun, whence the Bullet might casually receive some lateral impulse from the nose of the peece at the parting from it.
  • 2. The yielding of the Table which was sensible.
  • 3. The difficulty of aiming well by the Sight and But∣ton so far from the Mark.

Page  234Therefore to avoid all these, the Experiments I caus'd to be made before you in the Gallery of this Colledge, you may be pleased to remember were performed, first, taking only eight grains of Powder for the charge. Secondly, lay∣ing the Engine upon the floor, and thirdly, aiming by a thread at M, a mark about an Inch and ¾ from the mouth of the Gun (the edge of a knife being put for the mark the better to discern the line that was shot in) and they thus succeeded.

When the piece was fastned to the floor both at R and L, the Bullet then did so fully hit the mark, that it was divided by it into two parts, whose difference in weight was less than ten grains (about the thirty third part of the whole Bullet) although the lesser part was a little hol∣low, and that from which the neck of Lead was a little too close pared off: But when hindred from Recoiling only at R, the Bullet mist the mark towards L or A, for the whole Bullet, less than two grains excepted, went on that side: And in like manner when hindred from Re∣coiling at L, the Bullet mist the mark towards R or B, the whole Bullet, less than two grains excepted, passing the knife on that side thereof.

I had the honour to make other Experiments with the same Engine, lately at White-Hall before his Majesty and his Highness Royal within the Tilt-yard Gallery, where there is the hearth of a Chimney raised a little above the floor, about the distance of thirteen feet from the opposite wall, against which I caused a Plank to be placed, and the Engine to be laid first against the middle of the Hearth, that it might not recoil at all, and that part of the board to be marked against which 'twas levelled, known by a line stretched from the Breech of the Peece unto the Board, directly over the sight and button, and the fire be∣ing given (the charge being but eight grains of Powder Page  235 as before) the Bullet did fully hit the mark. Secondly, the Peece (charged and levelled in the same manner) was laid at the end of the Hearth next the Park, so that ve∣ry little of the corner R rested against it, and then the Bullet miss'd the mark about an inch and a quarter to∣wards the Park or A. The like being done at the other end of the Hearth, the Bullet then miss'd the mark as much the other way; and afterwards with double that charge something more, as before I had found it less with a smaller charge.

Since this (at first designing only to experiment the se∣veral distances that the bullet is carried wide of the mark with different charges of Powder) I made these Experiments following.

In the first Colume whereof you have the corner stopt from recoiling.

In the second the grains of Powder with which the Peece was charged.

In the third the distance the Bullet was shot wide from the mark in inches, tenths, and parts of tenths.

In the fourth the side on which the Bullet was car∣ried.

In the last the distance of the mark from the muzzle of the Gun in feet.

Page  236

L120.6¼R2L960.2L L40.1½R¼L640.0⅛R¼

Page  237Whence you may be pleased to observe:

First, That the recoil of the Peece being hindred only at R or L, whatsoever be the charge of the Powder, the Bullet still misses the mark, placed at the mouth of the Gun, on the same side that the recoil is made.

Secondly, That about twelve grains of Powder shoots widest from the mark at all distances above mentioned, on the same side that the Recoil is made.

Thirdly, That above forty eight grains of Powder shoots wide from the mark, placed at nine foot from the muz∣zle of the Peece, on the contrary side to that on which the recoil is made.

The cause of the first I cannot doubt to be the recoil of the Peece (from the force of the Powder) before the Bullet be parted from it.

The second is, as I conceive, because with less than twelve grains the Peece ceaseth to recoil before the Bullet be parted from it. And with more than twelve grains the Bullet is parted from the Peece before it hath recoiled so far: A greater power not moving a greater weight swifter (horizontally) in the same proportion that it doth the lesser.

And for the third I have this to offer, viz Because the mouth of the Gun is moving sidewards whilst the Bullet is going out; Therefore the mouth of the Peece must be contiguous (at least) unto the Bullet on the con∣trary side to that on which the Peece recoils, some time after the separation made on the other side, and therefore the last impulse of the Bullet from the force of the Powder is on that side the Peece recoils, wherefore the Bullet must necessarily cross the Axis of the Peece, and that with a greater or lesser Angle, according to the force of the Pow∣der, & when this Angle therefore is greater than the An∣gle of recoil, then must the Axis of that Cylinder in which Page  238 the Bullet moues cross the Axis of the mark, beyond which interjection the mark being placed, the Bullet must be carried necessarily wide of the mark on the contrary side to the recoil of the Peece.


fek=flp=phm= the Angle of Recoile phn the Angle of Reflexi∣on made at the parting of the Bullet from the Peece. When phn>phm (mh being alwayes parallel to fg) then must hn enter∣sect fg if continued.

Some other Experiments I have also made with ano∣ther Peece (about the same length, but of a bore neer two tenths of an inch less) and ordered in the same manner, and do find, that with a small charge the Bullet is shot (thence too) wide of the mark on the same side on which the Recoil is made, and with a full charge wide the con∣trary side.

Page  239I caused besides two Pistol barrels of about five inches long to be placed upon Carriages with four Wheels,*and loaded with lead, that they might not overturn when dis∣charged, and both of equal weight, and an Iron Cylinder of the length of both their bores, and of the same diameter with a piece of Lead of weight equal to it. So that the piece of Lead affixed to either of these Guns (which of them I should please to charge) might equally poise the other with the Iron Cylinder. And thus indifferently charging either with eight grains more or less of Powder, and putting the Iron Cylinder home into both, the piece of Lead being affixed to that which held the Powder, and then both so set upon the floor and the Powder fired, I could not thereby discover, that the charged Peece, or the other, either of them, did certainly recoil more or less than the other, they rather seemed still to be equal.

These few Experiments I have made since, the Barrel being first cut at the muzzle, parallel to a vertical plain passing the line CD.


Page  240Besides these, there is another that I shall mention, and that is the Experiment it self, or the Double-Bottom'd-Ship, invented by Sir William Petty: of this I will venture to add a few words, and I think I may do it, without transgressing that Rule I had fix'd to my self, of not enlarging on the praise of particular Names, or Designs. For since the Experiment it self is lost, I hope I may securely speak of its advantages: seeing men are wont out of common humanity to al∣low the commendations of dead Men, I trust I may commend a wreck'd Ship, without any fear of the en∣vy that may thence arise to the Author. In brief there∣fore I will say this of it, that it was the most conside∣rable Experiment, that has been made in this Age of Experiments: if either we regard the great charge of the work, or the wonderful change it was likely to make in Navigation, or the great success, to which this first Attempt was arriv'd. Though it was at first con∣fronted with the doubts, and Objections of most Sea∣men of our Nation, yet it soon confuted them by Ex∣perience. It appear'd very much to excel all other forms of Ships, in sayling, in carriage, in security, and many other such benefits. Its first Voyage it perform'd with admirable swiftness. And though it miscarried after its return, yet it was destroyed by a common fate, and by such a dreadful tempest, as overwhelm'd a great Fleet the same night: so that the Antient Fa∣bricks of Ships have no reason to triumph over that new Model, when of the threescore and ten sail that were in the same Storm, there was not one escap'd to bring the News.

In a word, though this Invention succeeded not, while it was only supported by private Purses: it will undoubtedly produce great effects, if ever it shall Page  241 be retreiv'd upon the publick Stock of a Nation: which will be able to sustain the first hazards, and losses that must be allow'd to happen in the begin∣nings of all extraordinary Trials.

To their Experiments I will subjoin their Observa∣tions,* which differ but in name from the other, the same fidelity, and truth being regarded in collecting them both.

Observations of the fix'd Stars for the perfecting of Astronomy, by the help of Telescopes: of the Comets in 1665, and 1666. which were made both in London, and elsewhere; and particularly of the first Comet, for above a month after, it disappear'd to the naked eye, and became Stationary, and Retrograde.

Observations about Saturn, of the proportion, and position of its Ring, of the Motion and Orbit of its Lunale, of the shadow of the Ring on the Body, and of the Body on the Ring; and of its Phases, &c. of Iu∣piters Belts, and of its spots, and verticity about its Axis, of its eclipsing its Satellites, and being eclips'd by them; of the Orbs, Inclinations, Motions, &c. of the Satellites, together with Tables, and Ephemerides of their motions.

Observations of the Spots about the Body of Mars, and of its whirling motion about its Center: of se∣veral Eclipses of the Sun, and Moon, and some of them as were not taken notice of, by Astronomers, or Ta∣bles commonly us'd: of the Spots in the Moon, and of the several appearances in the Phases of it: of the Moon at the same time, by Correspondents in several parts of the World, towards the finding her Parallax, and distance.

Observations of the Eliptical and waved Figures Page  242 of the Planetary Bodies, neer the Horizon from the re∣fraction of the Hemisphere: of the effects of Light∣ning: of the various pressure of the Atmosphere, by a Wheel-barometer for several years, and of its usefulness for predicting the changes of Weather.

Observations on frozen Beer: on the Figures of Snow frozen Water, Vrine congeal'd: on the suspen∣sion of Mercury at a great height: on Mines, and Mi∣nerals: on the Concretions of Wood, Plants, Shells, and several Animal Substances: on the effects of Earthquakes, Fiery Eruptions, and Inundations: on Lakes, Mountains, Damps, subterraneous Fires: on Tides, Currents, and the Depth of the Sea.

Observations of the liming of Ground, for improve∣ment of the Bodies of Sheep, but spoiling their Wool: of several wayes for preventing smutty Corn: of the importance of changing Seed-corn: of the alteration of the Horns of Sheep, and other Cattel, by the change of Pasture: of the Pores and Valies in Wood: the Anatomy of Trees: of the sensitive, and humble Plant.

Observations on the Bills of Mortality: on the leaves of Sage: on small living Flies in the Powder of Cantharides: of Insects bred in Dew: of Virginian Silk-Bottoms: of the Parts, and Anatomy of Fishes: of the Teeth of Lupus Marinus, that they are the same thing with the Toad-stones set in Rings: of the Re∣spiration of Fishes: of Bernacles: of the calcin'd Powder of Toads: of an Outlandish Deer-skin, and hair: of the Parts of Vipers: of Stones taken out of the Heart of a Man: of young Vipers, that they do not eat holes through their old ones Bellies, as is com∣monly affirm'd.

For Examples of this Head, I will only refer my Page  243 Reader to those which Mr. Graunt has publish'd on the Bills of Mortality; wherein the Author has shewn, that the meanest and most trivial matters may be so cultivated, as to bear excellent Fruit, when they come under the management of an accurate, and prudent Observer: For from those Papers, which went about so many years, through every Tradesmans hands, without any manner of profit, except only to the Clerks that collected them, he has deduc'd many true Conclusions, concerning the gravest, and most weighty Parts of Civil Government, and humane Na∣ture.

As I am now passing away from their Experiments.* and Observations, which have been their proper, and principal work: there comes before me an Objection, which is the more to be regarded, because it is rais'd by the Experimenters themselves. For it is their com∣mon complaint, that there is a great nicety, and con∣tingency, in the making of many Experiments: that their success is very often various, and inconstant, not only in the hands of different, but even of the same Triers. From hence they suggest their fears, that this continuance of Experimenters, of which we talk so much, will not prove so advantageous, though they shall be all equally cautious in observing, and faithful in recording their Discoveries: because it is probable, that the Trials of Future Ages will not agree with those of the present, but frequently thwart, and con∣tradict them.

The Objection is strong, and material; and I am so far from diminishing the weight of it, that I am ra∣ther willing to add more to it. I confess many Expe∣riments are obnoxious to failing; either by reason of Page  244 some circumstances, which are scarce discernable, till the work be over: or from the diversity of Materi∣als, whereof some may be genuine, some sophisticated, some simple, some mix'd, some fresh, some may have lost their virtue. And this is chiefly remarkable, in Chy∣mical Operations, wherein if the dissolvents be ill pre∣par'd, if the Spirits be too much, or too little purify'd, if there be the least alteration, in the degree of Fire, the quantity of Matter, or by the negligence of those that attend it, the whole course will be overthrown, or chang'd from its first purpose.

But what is now to be concluded from hence? shall this instability, and Casualty of Experiments, deter us from labouring in them at all? or should it not rather excite us to be more curious and watchful in their process? It is to be allow'd that such underta∣kings are wonderfully hazardous and difficult; why else does the Royal Society indeavour to preserve them from degenerating, by so many forewarnings, and rules, and a Method so severe? It is granted, that their event is often uncertain, and not answerable to our expectations. But that only ought to admonish us, of the indispensable necessity of a jealous, and exact Inquiry. If the uncertainty proceeded from a constant irregularity of Nature, we had reason then to despair: but seeing it for the most part arises only from some defect or change in our progress, we should thence learn, first to correct our own miscarriages, before we cease to hope for the success.

Let then the Experiment be often renew'd. If the same kinds, and proportions of Ingredients be us'd, and the same circumstances be punctually observ'd, the effect without all question will be the same. If some little variation of any of these, has made any altera∣tion, Page  245 a judicious, and well practis'd Trier will soon be able to discern the cause of it; and to rectifie it, upon the next repetition. If the difference of time, or place, or matter, or Instruments, will not suffer the pro∣duct to be just the same in all points: yet something else will result, that may prove perhaps as beneficial. If we cannot alwayes arrive at the main end of our Labours, some less unsought Curiosities will arise. If we cannot obtain that which shall be useful for pra∣ctice, there may something appear that may in∣struct.

It is strange that we are not able to inculcate into the minds of many men, the necessity of that distin∣ction of my Lord Bacons, that there ought to be Ex∣periments of Light, as well as of Fruit. It is their usu∣al word, What solid good will come from thence? They are indeed to be commended for being so severe Ex∣actors of goodness. And it were to be wish'd, that they would not only exercise this vigour, about Expe∣riments, but on their own lives▪ and actions: that they would still question with themselves, in all that they do; what solid good will come from thence? But they are to know, that in so large, and so various an Art as this of Experiments, there are many degrees of usefulness: some may serve for real, and plain benefit, without much delight: some for teaching without apparent profit: some for light now, and for use here∣after; some only for ornament, and curiosity. If they will persist in contemning all Experiments; except those which bring with them immediate gain, and a present harvest: they may as well cavil at the Provi∣dence of God, that he has not made all the seasons of the year, to be times of mowing, reaping, and vin∣tage.

Page  246*Of the variety, and excellence of the Instruments, with which this Age abounds, for their help in Philo∣sophical matters, I have already discoursed in the for∣mer Part. I will now go on to mention those new ones, which they themselves, or some of their Mem∣bers, have either invented, or advanc'd, for the ease, strength, and direction of their senses, in the motions of Nature, and Art: of this kind are these that fol∣low.

An Instrument for finding a second of Time by the Sun: another for finding the Celestial Refracti∣ons.

Three several Quadrants made after three new contrivances, which though they are not above eigh∣teen Inches in Diameter, and so are manageable in any Window, or Turret, are yet far more exact, than the best, that have been hitherto us'd, for Astronomical Observations, or taking Angles at Land.

A new Instrument for taking Angles by reflection; by which means the Eye at the same time sees the two Objects, both as touching in the same point, though distant almost to a Semicircle: which is of great use for making exact Observations at Sea.

A new kind of Back-staff for taking the Suns alti∣tude by the Shadow, and Horizon: which is so con∣triv'd, that though the shadow be at three foot di∣stance, or as much more as is desir'd, yet there shall not be the least Penumbra: and the Shadow may be easi∣ly distinguish'd to the fourth part of a minute.

A Hoop of all the fix'd Stars in the Zodiac, for the speedy finding the Position of the Ecliptic, and for knowing the extent of the Constellations.

A Copernican Sphere, representing the whirling Page  247 Motion of the Sun, and the Motion of the several Planets.

A great many new wayes of making Instruments, for keeping time very exactly, both with Pendulums, and without them: whereby the intervals of time may be measur'd both on the Land, and Sea.

A universal Standard, or measure of Magnitudes, by the help of a Pendulum, never before attempt∣ed.

A new kind of Pendulum Clock, wherein the Pen∣dulum moves circularly, going with the most simple, and natural motion, moving very equally, and making no kind of noise.

A Pendulum Clock shewing the aequation of Time.

Three new wayes of Pendulums for Clocks, and se∣veral wayes of applying the motion of the Watch∣work to them.

Several new kinds of Pendulum Watches for the Pocket, wherein the motion is regulated, by Springs, or Weights, or Loadstones, or Flies moving very ex∣actly regular.

Several sorts of Instruments for compressing, and rarefying the Air: A Wheel-Barometer, and other Instruments for finding the pressure of the Air, and serving to predict the changes of the Weather.

A new kind of Scales, for examining the gravity of Bodies in all places: to see whether the attraction of the Earth, be not greater in some parts of the Earth, than in others, and whether it do not decrease, at farther distances from the surface of the Earth; either upwards into the Air, or downwards under the Earth.

A very exact pair of Scales, for trying a great num∣ber of Magnetical Experiments.

Page  248Several very accurate Beams, for trying many Sta∣tical Experiments, and for finding the most exact gra∣vity of several kinds of Bodies.

A great number of Magnetical Instruments, for ma∣king Experiments about Loadstones.

Several new kinds of Levels for finding the true Horizon, where, by one of not above a foot length, the Horizontal line may be found, without the error of many seconds.

A new kind of Augar for boring the ground, and fetching up whatever it meets with in the right or∣der.

A new Instrument for fetching up any Substance from the bottom of the Sea, whether Sand, Shels, Clay, Stones, Minerals, Metals.

A new Bucket for examining and fetching up what∣ever Water is to be found at the bottom of the Sea, or at any dept, and for bringing it up without mix∣ing with the other Water of the Sea, through which it passes.

Two new wayes of sounding the depth of the Sea without a Line, for examining the greatest dept of the Ocean, in those parts of it, that are most remote from the Land.

Several Instruments for finding the velocity of swimming Bodies of several Figures, and mov'd with divers strengths, and for trying what Figures are least apt to be overturn'd, in order to the making a true Theory, of the Forms of Ships, and Boats for all uses.

An Instrument of great height, with Glass-windows on the sides, to be fill'd with Water, for examining the velocity of Bodies of several Substances, Figures and Magnitudes, by their descent.

Page  249An Instrument for measuring, and dividing the time of their Descent, to the accurateness of two, or three thirds of time, serving also for examining the swiftness of Bodies descending through the Air, and of Bodies shot by a Gun, or Bow.

A Bell for diving under water to a great depth, wherein a man has continued at a considerable depth under water, for half an hour, without the least in∣convenience.

Another Instrument for a Diver, wherein he may continue long under water, and may walk to and fro, and make use of his strength, and limbs, almost as free∣ly as in the Air.

A new sort of Spectacles, whereby a Diver may see any thing distinctly under Water.

A new way of conveighing the Air under Water, to any Depth, for the use of Divers.

An Instrument for measuring the swiftness, and strength of the Wind.

An Instrument for the raising a continual stream of Water, by turning round a moveable valve, within the hollow of a close Cylindrical Barrel.

Several kinds of Thermometers for discovering the heat, and cold of the Air, or any other Liquors: a Thermometer for examining all the degrees of heat in Flames, and Fires, made of several Substances; as al∣so the degrees of heat requisite to melt Soder, Lead, Tin, Silver, Brass, Iron, Copper, Gold.

A Standard for Cold several wayes.

An Instrument for planting of Corn.

Four several sorts of Hygroscopes made with several Substances, for discovering the drowth, and moisture of the Air.

Several kinds of ways to examine the goodness, and badness of Waters.

Page  250Several Engines for finding, and determining the force of Gun-powder, by Weights, Springs, Sliding, &c.

An Instrument for receiving, and preserving the force of Gun-powder, so as to make it applicable, for the performing of any motion desir'd.

Several Instruments for examining the recoiling, true carriage, and divers other proprieties of Guns.

Several kinds of Otocousticons, or Instruments to im∣prove the sense of hearing.

Several Models of Chariots, and other Instruments, for Progressive Motion.

A Chariot-way-wiser, measuring exactly the length of the way of the Chariot, or Coach to which it is ap∣ply'd.

An Instrument for making Screws with great di∣spatch.

A way of preserving the most exact impression of a Seal, Medal, Sculpture; and that in a Metal harder than Silver.

An Instrument for grinding Optick-glasses: a dou∣ble Telescope: several excellent Telescopes of divers lengths, of six, twelve, twenty eight, thirty six, sixty foot long, with a convenient Apparatus for the mana∣ging of them: and several contrivances in them for measuring the Diameters, and parts of the Planets, and for finding the true position, and distance of the small fix'd Stars, and Satellites.

Towards the exactness of all manner of these Op∣tick-glasses, the English have got a great advantage of late years, by the Art of making Glass, finer, and more serviceable for Microscopes, and Telescopes, than that of Venice. This Invention was brought into our Coun∣try, Page  251 and practis'd here, by the care, and expence of the Duke of Buckingham; whom the Author of these Papers ought to mention with all honour; both for his Skill and Zeal in advancing such Experimental Stu∣dies of which I am writing: and also because it has been by the favour of so great a Patron, that I have injoy'd the leisure, and convenience of composing this History.

As soon as they were reduc'd into a Fix'd Assembly,* one of the Principal Intentions they propos'd to ac∣complish, was a General Collection of all the Effects of Arts, and the Common, or Monstrous Works of Na∣ture. This they at first began by the casual Presents, which either Strangers, or any of their own Members bestow'd upon them. And in short time it has in∣creas'd so fast, by a contribution from all Parts, and chiefly by the bounty of Mr. Colwal, that they have already drawn together into one Room, the greatest part of all the several kinds of things, that are scat∣ter'd throughout the Vniverse. The Keeping, and Ranging of these into order, is committed to Mr. Hook, who had also the honour of being made the first Curator of the Royal Society by electi∣on. This Repository he has begun to reduce under its several heads, according to the exact Method of the Ranks of all the Species of Nature, which has been compos'd by Doctor Wilkins, and will shortly be pub∣lish'd in his Vniversal Language: A Work wherein this excellent Man has undertaken a Design, that very well fits the temper of his own Mind; for it well became him to teach a Communion of Speech a∣mongst all Philosophers; whose chief study it has al∣wayes been, to promote a general agreement, and Page  252 correspondence amongst all Virtuous and Wise men.

This Book had sooner seen the light, if part of it had not perish'd in the Fire. Of its use and accurate composition there is no man can doubt, that has ever heard the name of the Author: of whom, if I had not at first restrain'd my self from particular commenda∣tions, I might have said very much in his praise, which deserves to be known to all the World, and to be the first Experiment of his own Vniversal Language.

* Having well succeeded in this their purpose of col∣lecting divers patterns of all Natural, and Artificial things: they have also (amongst others) appointed a Committee, whose chief employment shall be to read over whatever Books have been written on such sub∣jects. By this means they hope speedily to observe, and digest into Manuscript volumes, all that has been hitherto try'd, or propounded in such studies. This is the only help that an Experimenter can receive from Books: which he may still use, as his Guides, though not as his Masters. For this end they have begun a Library consisting only of such Authors, as may be ser∣viceable to their Design. To this there has been late∣ly made a great Addition, by the Munificent Gift of Mr. Henry Howard of Norfolk, who has bestow'd on the Society the whole Arundelian Library, containing several hundreds of choice Manuscripts, besides some thousands of other Books of all kinds. And because many of them belong'd to other Professions, this No∣ble Benefactor has given them with a free permission of changing them for others, that shall be more pro∣per for their Work: Whereby they will shortly be able to shew a compleat Collection of all that has been Page  253 publish'd in the Antient, or Modern Tongues, which either regards the productions of Nature, or the effects of all Manual Arts.

Nor is this the only bounty which this Illustrious Person has conferr'd on the Royal Society; since by the firing of London, the first place of their meeting has been restor'd to its original use, and made an Ex∣change, he has afforded them a retreat in his own house, where they assemble at this present: By which favour he has added a new honour to the antient No∣bility of his Race: one of his Ancestors had before adorn'd that place with many of the best Monu∣ments of Antiquity: And now by entertaining these new discoveries under his Roof, his Family deserves the double praise of having cherish'd both the old, and new Learning; so that now methinks in Arundel house, there is a perfect representation, what the Real Philosophy ought to be: As there we behold new In∣ventions to flourish amongst the Marbles, and Images of the Dead: so the present Arts, that are now rising, should not aim at the destruction of those that are past, but be content to thrive in their company.

It will not I hope be expected,* that I should present my Reader an Index of all the several Writings, which have at any time been publish'd by the Members of the Royal Society I shall omit those, which either were printed before the beginning of this Institution, or which treat of matters, that have no relation to their Design. Only I will say in general, that there is scarce any Art, or Argument, which has ever been the sub∣ject of humane Wit, of which I might not produce In∣stances, that some Fellows of this Society have given good proofs of their labours in it: of those Discour∣ses,Page  254 which have been since compos'd by some of their Body, or read before their weekly Assemblies, and di∣rectly concern the advancement of their Work, these are the principal.

Several Hypotheses explaining the divers Phases and Motions, and other Phaenomena of the Comets.

Several Hypotheses of Saturn, and its Satelles.

An Hypothesis of the cause of the Rugosity of the Moons surface.

An Hypothesis of the motion of the Moon, and of the Sea depending upon it.

An Hypothesis of the Motion of the Planets, and of Circular Motion in general.

Several Hypotheses for the Aequation of Time.

A Discourse about the possibility of the Retardati∣on of Coelestial Motions, and of their going slower, and slower, the longer they last.

A Discourse of making the several Vibrations of a Pendulum aequal, by making the weight of it move in a Cycloid instead of a Circle.

Several Discourses, and Hypotheses about the length of a Pendulum, for moving once in a second of Time.

A Discourse of the most convenient length of a Pen∣dulum, for making a Standard for a universal Measure.

Several Astronomical Discourses of Mr. Horrex re∣triv'd, and digested for the Press.

Vleg Beg translated, about the places of the fix'd Stars, and several other Astronomical Observations.

A Discourse about the possibility of the change of the attractive power of the Earth, and consequently of the variation of the vibrative motion of Pendu∣lums.

A Discourse about short inclining Pendulums, and of other Pendulums counterpois'd above the Center of Page  255Motion, and of others lying Horizontal in the manner of a Beam.

An Hypothesis about Fire, and Flame.

An Hypothesis, and discourse of the gravity, pres∣sure, and spring of the Air.

A Discourse of an Air Register.

Several Discourses Mathematical, and Philosophi∣cal, upon the Experiment of raising great weights by the Breath.

A Discourse and Demonstration against a propos'd Method of doubling the Cube, and of finding two mean Proportionals.

Several Discourses about Thermometers, Hygroscopes, Baroscopes, and other Weather-wisers.

An Hypothesis and Discourse of the Inflection and inflective veins of the Air, and of the fitness, and unfit∣ness of the Air for Coelestial Observations.

An Hypothesis of the Form, and Spring of the Air.

A Discourse of the different parts of the same Wa∣ter, and of the difference of Waters.

A Discourse and Hypothesis of Filtration, and of the Congruity, and Incongruity of Bodies.

A Discourse of the possible height of the Air, and of its proportionable rarefaction upwards.

An Hypothetical Discourse about the suspension of the Clouds, and their pressure.

An Hypothesis, and Discourse of Earthquakes.

A Discourse of Petrifactions, and an Hypothesis for explaining the several varieties of such Bodies.

Several Discourses about the Loadstone, and an Hy∣pothesis for salving its appearances.

A Discourse about the Pores of Stones.

A Discourse about Eggs.

A Discourse concerning the Glass-drops.

Page  256A Discourse and Hypothesis of annealing, and temper∣ing Steel.

Discourses about Cyder, and Coffee.

A Discourse of the original of Forms.

An Hypothesis of Light.

A Discourse and Hypothesis of the Nature and Pro∣prieties of Colours.

A Discourse about improving Wood for Dying, and for fixing Colours.

A Discourse about the improvement of Musick.

A Discourse of the differing Heat of Summer, and Winter:

A Discourse, and Hypothesis about Fluidity.

Discourses upon several Mercurial Experiments.

Discourses of Hydrostaticks.

Discourses about the force of falling Bodies.

A Treatise of the motion of the Muscles.

A Discourse of the usefulness of Experimental Phi∣losophy.

A Treatise of the vanity of Dogmatizing.

The Sceptical Chymist.

Essayes about Salt-peter.

The Parallel of the Antient, and Modern Archi∣tecture.

Microscopical Observations.

Micrographia, or a Discourse of things discover'd by a Microscope.

Three Books of Feavors, of the Brain, and of the Scurvy, which I will alledge as the great Instances of this head: Wherein the Famous Author has with ac∣curate diligence made prodigious improvements in all the parts of Physick, and shewn that the largeness of his Knowledge in it, is equal to the happy success of his practice.

Page  257In this Collection of their Discourses, and Treatises, my Reader beholding so many to pass under the name of Hypotheses, may perhaps imagine that this consists not so well with their Method, and with the main purpose of their Studies, which I have often re∣peated to be chiefly bent upon the Operative, rather than the Theoretical Philosophy. But I hope he will be satisfied, if he shall remember, that I have already re∣mov'd this doubt, by affirming, that whatever Prin∣ciples, and Speculations they now raise from things, they do not rely upon them as the absolute end, but only use them as a means of farther Knowledge. This way the most speculative Notions, and Theorems that can be drawn from matter, may conduce to much profit. The light of Science, and Doctrines of cau∣ses, may serve exceeding well to promote our Experi∣menting; but they would rather obscure, than illu∣minate the mind, if we should only make them the perpetual Objects of our Contemplation: as we see the light of the Sun, is most beneficial to direct our footsteps in walking, and our hands in working, which would certainly make us blind, if we should only continue fix'd, and gazing on its Beams.

The Histories they have gather'd are either of Na∣ture,*Arts, or Works. These they have begun to col∣lect by the plainest Method, and from the plainest In∣formation. They have fetch'd their Intelligence from the constant and unerring use of experienc'd Men of the most unaffected, and most unartificial kinds of life. They have already perform'd much in this way, and more they can promise the world to accomplish in a very short space of Time.

There are already brought in to them the HistoryPage  258 of Comets in general, and especially of the two last: The History of English Mines, and Oars: and particu∣larly two several Histories of Tinneries and Tin-work∣ing.

The Histories of Iron-making: of Lignum Fossile: of Saffron: of Alkermes: of Verdigreace: of whi∣ting of Wax: of Cold: of Colours: of Fluidity, and firmness.

The Histories of Refining: of making Copperas: of making Allum: of Salt-peter: of making Latten: of Lead: of making Salt out of Sea-water: of re∣fining Gold: of making Pot-Ashes: of making Ce∣ruse: of making Brass: of Painting, and Limning: of Calcography: of Enamelling: of Varnishing: of Dying.

The Histories of making Cloth: of Worsted-Combers: of Fullers: of Tanners, and Leather-ma∣king: of Glovers, and Leather-dressing: of Parch∣ment, and Vellum-making, and the way of making transparent Parchment: of Paper-making: of Hat∣ters: of making Marble-paper: of the Rowling-Press.

The Histories of making Bread: of Malt: of brew∣ing Beer and Ale in several places: of Whale-fishing: of the Weather for several years: of Wind-mills, and other Mills in Holland: of Masonry: of Pitch and Tar: of Maiz: of Vintners: of Shot: of ma∣king Gun-powder: and of making some, that is twenty times as strong as the common Pistol-pow∣der.

The two last of these were communicated to the Royal Society by the favour of Prince Rupert; whom I take the boldness to mention here, for his excellent Knowledge, and use in all manner of Mechanical Page  259 Operations. But his name will be recorded in all the Histories of this time, for greater works, for many glorious Enterprises by Sea and Land, and for the Im∣mortal Benefits whereby he has oblig'd the English Nation.

The Instances that I shall give of this their manner of collecting Histories, shall be, of Works, that of Salt-peter, of Arts, that of Dying, of Nature, that of Oysters: which last may perhaps seem a subject too mean to be particularly alledg'd; but to me it appears worthy to be produc'd. For though the British Oysters have been famous in the World, ever since this Island was discover'd, yet the skill how to order them aright, has been so little consider'd amongst our selves, that we see at this day, it is confin'd to some few narrow Creeks of one single County.