Chapter III: Preface (2)

The Instrument consisted of five Rulers, or long pieces placed
together, after the manner exprest in the second Figure of the first
_Scheme_, where AB denotes a straight piece of wood about six foot and
two inches long, about three inches over, and an inch and half thick,
on the back side of which was hung a small plummet by a line stretcht
from top to bottom, by which this piece was set exactly upright, and so
very firmly fixt; in the middle of this was made a hole or center, into
which one end of a hollow cylindrical brass Box CC, fashion’d as I
shall by and by describe, was plac’d, and could very easily and truly
be mov’d to and fro; the other end of this Box being put into, and
moving in, a hole made in a small arm DD; into this box was fastned the
long Ruler EF, about three foot and three or four inches long, and at
three foot from the above mention’d Centers PP was a hole E, cut
through, and cross’d with two small threads, and at the end of it was
fixt a small sight G, and on the back side of it was fixt a small Arm
H, with a Screw to fix it in any place on the Ruler LM; this Ruler LM
was mov’d on the Center B (which was exactly three foot distance from
the middle Center P) and a line drawn through the middle of it LM, was
divided by a Line of cords into some sixty degrees, and each degree was
subdivided into minutes, so that putting the cross of the threads in E
upon any part of this divided line, I presently knew what Angle the two
Rules AB and EF made with each other, and by turning the Screw in H, I
could fix them in any position. The other Ruler also RS was made much
after the same manner, only it was not fixt to the hollow cylindrical
Box, but, by means of two small brass Armes or Ears, it mov’d on the
Centers of it; this also, by means of the cross threads in the hole S,
and by a Screw in K, could be fastned on any division of another line
of cords of the same radius drawn on NO. And so by that means, the
Angle made by the two Rulers, AB and RS, was also known. The Brass box
CC in the middle was shap’d very much like the Figure X, that is, it
was a cylindrical Box stopp’d close at either end, off of which a part
both of the sides and bottomes was cut out, so that the Box, when the
Pipe and that was joyned to it, would contain the Water when fill’d
half full, and would likewise, without running over, indure to be
inclin’d to an Angle, equal to that of the greatest refraction of
Water, and no more, without running over. The Ruler EF was fixt very
fast to the Pipe V, so that the Pipe V directed the length of the Ruler
EF, and the Box and Ruler were mov’d on the Pin TT, so as to make any
desirable Angle with the Ruler AB. The bottom of this Pipe V was stop’d
with a small piece of exactly plain Glass, which was plac’d exactly
perpendicular to the Line of direction, or _Axis_ of the Ruler EF. The
Pins also TT were drill’d with small holes through the _Axis_, and
through those holes was stretcht and fastned a small Wire. There was
likewise a small Pipe of Tin loosly put on upon the end of V, and
reaching down to the sight G; the use of which was only to keep any
false Rayes of light from passing through the bottom of V, and only
admitting such to pass as pierced through the sight G: All things being
placed together in the manner describ’d in the Figure; that is, the
Ruler AB being fixt perpendicular, I fill’d the Box CC with Water, or
any other Liquor, whose refraction I intended to try, till the Wire
passing through the middle of it were just covered: then I moved and
fixt the Ruler FE at any assignable Angle, and placed the flame of a
Candle just against the sight G; and looking through the sight I, I
moved the Ruler RS to and fro, till I perceived the light passing
through G to be covered, as ’twere, or divided by the dark Wire passing
through PP: then turning the Screw in K, I fixt it in that posture: And
through the hole S, I observed what degree and part of it was cut by
the cross threads in S. And this gave me the Angle of Inclination, APS
answering to the Angle of Refraction BPE: for the surface of the Liquor
in the Box will be alwayes horizontal, and consequently AB will be a
perpendicular to it; the Angle therefore APS will measure, or be the
Angle of Inclination in the Liquor; next EPB must be the Angle of
Refraction, for the Ray that passes through the sight G, passes also
perpendicularly through the Glass _Diaphragme_ at F, and consequently
also perpendicularly through the lower surface of the Liquor contiguous
to the Glass, and therefore suffers no refraction till it meet with the
horizontal surface of the Liquor in CC, which is determined by the two
Angles.

By means of this Instrument I can with _little trouble_, and a very small quantity of any _Liquor_, examine, most accurately, the _refraction_ of it not only for one inclination, but for all; and thereby am inabled to make very accurate Tables; several of which I have also experimentally made, and find, that _Oyl of Turpentine_ has a much greater Refraction then _Spirit of Wine_, though it be _lighter_; and that _Spirit of Wine_ has a greater Refraction then _Water_, though it be lighter also; but that _salt Water_ also has a greater Refraction then _fresh_, though it be _heavier_: but _Alum water_ has a less refraction then common _Water_, though heavier also. So that it seems, as to the _refraction_ made in a Liquor, the _specifick gravity_ is of no efficacy. By this I have also found that look what _proportion _the _Sine_ of the Angle of _one Inclination_ has to the _Sine_ of the Angle of _Refraction_, correspondent to it, the same _proportion_ have all the _Sines_ of other Inclinations to the _Sines_ of their appropriate Refractions.

My way for measuring how much a Glass magnifies an Object, plac’d at a
convenient distance from my eye, is this. Having rectifi’d the
_Microscope_, to see the desir’d Object through it very distinctly, at
the same time that I look upon the Object through the Glass with one
eye, I look upon other Objects at the same distance with my other bare
eye; by which means I am able, by the help of a _Ruler_ divided into
inches and small parts, and laid on the _Pedestal_ of the _Microscope_,
to cast, as it were, the magnifi’d appearance of the Object upon the
Ruler, and thereby exactly to measure the Diameter it appears of
through the Glass, which being compar’d with the Diameter it appears of
to the naked eye, will easily afford the quantity of its magnifying.

The _Microscope_, which for the most part I made use of, was shap’d
much like that in the sixth Figure of the first _Scheme_, the Tube
being for the most part not above six or seven inches long, though, by
reason it had four Drawers, it could very much be lengthened, as
occasion required; this was contriv’d with three Glasses; a small
Object Glass at A, a thinner Eye Glass about B, and a very deep one
about C: this I made use of only when I had occasion to see much of an
Object at once; the middle Glass conveying a very great company of
radiating Pencils, which would go another way, and throwing them upon
the deep Eye Glass. But when ever I had occasion to examine the small
parts of a Body more accurately, I took out the middle Glass, and only
made use of one Eye Glass with the Object Glass, for always the fewer
the Refractions are, the more bright and clear the Object appears. And
therefore ’tis not to be doubted, but could we make a_ Microscope _to
have one only refraction, it would, _cæteris paribus_, far excel any
other that had a greater number. And hence it is, that if you take a
very clear piece of a broken _Venice_ Glass, and in a Lamp draw it out
into very small hairs or threads, then holding the ends of these
threads in the flame, till they melt and run into a small round Globul,
or drop, which will hang at the end of the thread; and if further you
stick several of these upon the end of a stick with a little sealing
Wax, so as that the threads stand upwards, and then on a Whetstone
first grind off a good part of them, and afterward on a smooth Metal
plate, with a little Tripoly, rub them till they come to be very
smooth; if one of these be fixt with a little soft Wax against a small
needle hole, prick’d through a thin Plate of Brass, Lead, Pewter, or
any other Metal, and an Object, plac’d very near, be look’d at through
it, it will both magnifie and make some Objects more distinct then any
of the great _Microscopes_. But because these, though exceeding easily
made, are yet very troublesome to be us’d, because of their smalness,
and the nearness of the Object; therefore to prevent both these, and
yet have only two Refractions, I provided me a Tube of Brass, shap’d
much like that in the fourth Figure of the first _Scheme_; into the
smaller end of this I fixt with Wax a good _plano convex_ Object Glass,
with the convex side towards the Object, and into the bigger end I fixt
also with wax a pretty large plano _Convex_ Glass, with the _convex_
side towards my eye, then by means of the small hole by the side, I
fill’d the intermediate space between these two Glasses with very clear
Water, and with a Screw stopp’d it in; then putting on a Cell for the
Eye, I could perceive an Object more bright then I could when the
intermediate space was only fill’d with Air, but this, for other
inconveniences, I made but little use of.

My way for fixing both the Glass and Object to the Pedestal most
conveniently was thus: Upon one side of a round Pedestal AB, in the
sixth Figure of the first _Scheme_, was fixt a small Pillar CC, on this
was fitted a small Iron Arm D, which could be mov’d up and down, and
fixt in any part of the Pillar, by means of a small Screw E; on the end
of this Arm was a small Ball fitted into a kind of socket F, made in
the side of the Brass Ring G, through which the small end of the Tube
was screw’d; by means of which contrivance I could place and fix the
Tube in what posture I desir’d (which for many Observations was
exceeding necessary) and adjusten it most exactly to any Object.

For placing the Object, I made this contrivance; upon the end of a
small brass Link or Staple HH, I so fastned a round Plate II, that it
might be turn’d round upon its Center K, and going pretty stiff, would
stand fixt in any posture it was set; on the side of this was fixt a
small Pillar P, about three quarters of an inch high, and through the
top of this was thrust a small Iron pin M, whose top just stood over
the Center of the Plate; on this top I fixt a small Object, and by
means of these contrivances I was able to turn it into all kind of
positions, both to my Eye and the Light; for by moving round the small
Plate on its center, could move it one way, and by turning the Pin M, I
could move it another way, and this without stirring the Glass at all,
or at least but very little; the Plate likewise I could move to and fro
to any part of the Pedestal (which in many cases was very convenient)
and fix it also in any Position, by means of a Nut N, which was screw’d
on upon the lower part of the Pillar CC. All the other Contrivances are
obvious enough from the draught, and will need no description.

Now though this were the Instrument I made most use of, yet I have made several other Tryals with other kinds of Microscopes, which both for _matter_ and _form_ were very different from common spherical Glasses. I have made a _Microscope_ with one piece of Glass, both whose surfaces were _plains_. I have made another only with a _plano concave_, without any kind of reflection, divers also by means of _reflection_. I have made others of _Waters_, _Gums_, _Resins_, _Salts_, _Arsenick_, _Oyls_, and with divers other _mixtures of watery_ and _oyly Liquors_. And indeed the subject is capable of a great variety; but I find generally none more useful then that which is made with _two Glasses_, such as I have already describ’d.

What the things are I observ’d, the following descriptions will manifest; in brief, they were either _exceeding small Bodies_, or _exceeding small Pores_, or _exceeding small Motions_, some of each of which the Reader will find in the following Notes, and such, as I presume, (many of them at least) will be _new_, and perhaps not less _strange_: Some _specimen_ of each of which Heads the Reader will find in the subsequent delineations, and indeed of some more then I was willing there should be; which was occasioned by my first Intentions to print a much greater number then I have since found time to compleat. Of such therefore as I had, I selected only some few of every Head, which for some particulars seem’d most observable, rejecting the rest as superfluous to the present Design.

What each of the delineated Subjects are, the following descriptions annext to each will inform, of which I shall here, only once for all, add, That in divers of them the Gravers have pretty well follow’d my directions and draughts; and that in making of them, I indeavoured (as far as I was able) first to discover the true appearance, and next to make a plain representation of it. This I mention the rather, because of these kind of Objects there is much more difficulty to discover the true shape, then of those visible to the naked eye, the same Object seeming quite differing, in one position to the Light, from what it really is, and may be discover’d in another. And therefore I never began to make any draught before by many examinations in several lights, and in several positions to those lights, I had discover’d the true form. For it is exceeding difficult in some Objects, to distinguish between a _prominency_ and a _depression_, between a _shadow_ and a _black stain_, or a _reflection_ and a _whiteness in the colour_. Besides, the transparency of most Objects renders them yet much more difficult then if they were _opacous_. The Eyes of a Fly in one kind of light appear almost like a Lattice, drill’d through with abundance of small holes; which probably may be the Reason, why the Ingenious _Dr. Power_ seems to suppose them such. In the Sunshine they look like a Surface cover’d with golden Nails; in another posture, like a Surface cover’d with Pyramids; in another with Cones; and in other postures of quite other shapes; but that which exhibits the best, is the Light collected on the Object, by those means I have already describ’d.

And this was undertaken in prosecution of the Design which the _ROYAL SOCIETY_ has propos’d to it self. For the Members of the Assembly having before their eys so many _fatal_ Instances of the errors and falshoods, in which the greatest part of mankind has so long wandred, because they rely’d upon the strength of humane Reason alone, have begun anew to correct all _Hypotheses_ by sense, as Seamen do their _dead Reckonings_ by _Cœlestial Observations_; and to this purpose it has been their principal indeavour to _enlarge & strengthen_ the _Senses_ by _Medicine_, and by such _outward Instruments_ as are proper for their particular works. By this means they find some reason to suspect, that those effects of Bodies, which have been commonly attributed to _Qualities_, and those confess’d to be _occult_, are perform’d by the small _Machines_ of Nature, which are not to be discern’d without these helps, seeming the meer products of _Motion_, _Figure_, and _Magnitude_; and that the _Natural Textures_, which some call the _Plastick faculty_, may be made in _Looms_, which a greater perfection of Opticks may make discernable by these Glasses; so as now they are no more puzzled about them, then the vulgar are to conceive, how _Tapestry_ or _flowred Stuffs_ are woven. And the ends of all these Inquiries they intend to be the _Pleasure_ of Contemplative minds, but above all, the _ease and dispatch_ of the labours of mens hands. They do indeed neglect no opportunity to bring all the _rare_ things of Remote Countries within the compass of their knowledge and practice. But they still acknowledg their _most useful_ Informations to arise from _common_ things, and from _diversifying_ their most _ordinary_ operations upon them. They do not wholly reject Experiments of meer _light_ and _theory_; but they principally aim at such, whose Applications will _improve and facilitate_ the present way of _Manual Arts_. And though some men, who are perhaps taken up about less honourable Employments, are pleas’d to censure their proceedings, yet they can shew more _fruits_ of their first three years, wherein they have assembled, then any other _Society_ in _Europe_ can for a much larger space of time. ’Tis true, such undertakings as theirs do commonly meet with small incouragement, because men are generally rather taken with the _plausible_ and _discursive_, then the _real_ and the solid part of Philosophy; yet by the good fortune of their institution, in an Age of all others the most _inquisitive_, they have been assisted by the _contribution_ and _presence_ of very many of the chief _Nobility_ and _Gentry_, and others who are some of the _most considerable_ in their several Professions. But that that yet farther convinces me of the _Real esteem_ that the more _serious_ part of men have of this _Society_, is, that several _Merchants_, men who act in earnest (whose Object is _meum & tuum_, that great _Rudder_ of humane affairs) have adventur’d considerable sums of _Money_, to put in practice what some of our Members have contrived, and have continued _stedfast_ in their good opinions of such Indeavours, when not one of a hundred of the vulgar have believed their undertakings feasable. And it is also fit to be added, that they have one advantage peculiar to themselves, that very many of their number are _men of Converse and Traffick_; which is a good Omen, that their attempts will bring Philosophy from _words_ to _action_, seeing the men of Business have had so great a share in their first foundation.

And of this kind I ought not to conceal one particular _Generosity_, which more nearly concerns my self. It is the _munificence_ of _Sir John Cutler_, in endowing a Lecture for the promotion of _Mechanick Arts_, to be governed and directed by This _Society._This _Bounty_ I mention for the _Honourableness_ of the thing it self, and for the expectation which I have of the _efficacy_ of the _Example_; for it cannot now be objected to them, that their Designs will be esteemed _frivolous_ and _vain_, when they have such a _real Testimony_ of the _Approbation_ of a _Man_ that is such an _eminent Ornament_ of this renowned City, and one, who, by the _Variety_, and the _happy Success_, of his negotiations, has given evident proofs, that he is not easie to be deceiv’d. This Gentleman has well observ’d, that the _Arts_ of life have been too long _imprison’d_ in the dark shops of Mechanicks themselves, & there _hindred from growth_, either by ignorance, or self-interest: and he has bravely _freed_ them from these _inconveniences_: He hath not only obliged _Tradesmen_, but _Trade_ it self: He has done a work that is worthy of _London_, and has taught the chief City of Commerce in the world the right way how Commerce is to be improv’d. We have already seen many other great signs of Liberality and a large mind, from the same hand: For by his _diligence_ about the _Corporation for the Poor_; by his honorable _Subscriptions_ for the rebuilding of St. Paul’s; by his chearful _Disbursment_ for the replanting of _Ireland_, and by many other such _publick works_, he has shewn by what means he indeavours to _establish_ his Memory; and now by this last gift he has done that, which became one of the _wisest Citizens_ of our Nation to accomplish, seeing one of the _wisest of our Statesmen, the Lord Verulam_, first propounded it.

But to return to my Subject, from a digression, which, I hope, my Reader will pardon me, seeing the Example is so rare that I can make no more such digressions. If these my first Labours shall be any wayes useful to inquiring men, I must attribute the incouragement and promotion of them to a very _Reverend_ and _Learned Person_, of whom this ought in justice to be said, _That there is scarce any one Invention, which this Nation has produc’d in our Age, but it has some way or other been set forward by his assistance_. My Reader, I believe, will quickly ghess, that it is _Dr. Wilkins_ that I mean. He is indeed a man born for the _good_ of _mankind_, and for the _honour_ of his _Country_. In the _sweetness_ of whose _behaviour_, in the _calmness_ of his _mind_, in the _unbounded goodness_ of his _heart_, we have an evident Instance, what the true and the _primitive unpassionate Religion_ was, before it was _sowred_ by particular _Factions._ In a word, his _Zeal_ has been so _constant_ and _effectual_ in advancing all good and profitable _Arts, that_ as one of the Antient _Romans_ said of _Scipio_, _That he thanked God that he was a _Roman_; because whereever _Scipio_ had been born, there had been the seat of the Empire of the world_: So may I thank God, that _Dr. Wilkins_ was an _Englishman_, for whereever he had lived, there had been the chief Seat of _generous Knowledge_ and _true Philosophy_. To the truth of this, there are so many worthy men living that will subscribe, that I am confident, what I have here said, will not be looked upon, by any ingenious Reader, as a _Panegyrick_, but only as a _real testimony_.

By the Advice of this _Excellent man_ I first set upon this Enterprise, yet still came to it with much _Reluctancy_, because I was to follow the footsteps of so eminent a Person as _Dr. Wren_, who was the first that attempted any thing of this nature; whose original draughts do now make one of the Ornaments of that great Collection of Rarities in the _Kings Closet_. This _Honor_, which his first beginnings of this kind have receiv’d, to be admitted into the most famous place of the world, did not so much _incourage_, as the _hazard_ of coming after _Dr. Wren_ did _affright_ me; for of him I must affirm, that, since the time of _Archimedes_, there scarce ever met in one man, in so great a perfection, such a _Mechanical Hand_, and so _Philosophical_ a _Mind_.

But at last, being assured both by _Dr. Wilkins_, and _Dr. Wren_ himself, that he had given over his intentions of prosecuting it, and not finding that there was any else design’d the pursuing of it, I set upon this undertaking, and was not a little incourag’d to proceed in it, by the Honour the _Royal Society_ was pleas’d to favour me with, in approving of those draughts (which from time to time as I had an opportunity of describing) I presented to them. And particularly by the Incitements of divers of those Noble and excellent Persons of it, which were my more especial Friends, who were not less urgent with me for the publishing, then for the prosecution of them.

After I had almost compleated these Pictures and Observations (having had divers of them engraven, and was ready to send them to the Press) I was inform’d, that the Ingenious Physitian _Dr. Henry Power_ had made several _Microscopical_ Observations, which had I not afterwards, upon our interchangably viewing each others Papers, found that they were for the most part differing from mine, either in the Subject it self, or in the particulars taken notice of; and that his design was only to print Observations without Pictures, I had even then _suppressed_ what I had so far proceeded in. But being further _excited_ by several of my Friends, in compliance with their opinions, that it would not be unacceptable to several inquisitive Men, and hoping also, that I should thereby discover something New to the World, I have at length cast in my Mite, into the vast Treasury of _A Philosophical History_. And it is my _hope_, as well as _belief_, that these my _Labours_ will be no more comparable to the _Productions_ of many other _Natural Philosophers_, who are now every where busie about _greater_ things; then my _little Objects_ are to be compar’d to the greater and more beautiful _Works of Nature_, A Flea, a Mite, a Gnat, to an Horse, an Elephant, or a Lyon.

* * * * *

MICROGRAPHIA,

OR SOME

Physiological Descriptions

OF

MINUTE BODIES,

MADE BY

MAGNIFYING GLASSES;

WITH

OBSERVATIONS and INQUIRIES thereupon.

* * * * *

Observ. I. _Of the Point of a sharp small Needle._

As in _Geometry_, the most natural way of beginning is from a Mathematical _point_; so is the same method in Observations and _Natural history_ the most genuine, simple, and instructive. We must first endevour to make _letters_, and draw _single_ strokes true, before we venture to write whole _Sentences_, or to draw large _Pictures_. And in _Physical_ Enquiries, we must endevour to follow Nature in the more _plain_ and _easie_ ways she treads in the most _simple_ and _uncompounded bodies_, to trace her steps, and be acquainted with her manner of walking there, before we venture our selves into the multitude of _meanders_ she has in _bodies of a more complicated_ nature; lest, being unable to distinguish and judge of our way, we quickly lose both _Nature_ our Guide, and _our selves_ too, and are left to wander in the _labyrinth_ of groundless opinions; wanting both _judgment_, that _light_, and _experience_, that _clew_, which should direct our proceedings.

We will begin these our Inquiries therefore with the Observations of Bodies of the most _simple nature_ first, and so gradually proceed to those of a more _compounded_ one. In prosecution of which method, we shall begin with a _Physical point_; of which kind the _Point of a Needle_ is commonly reckon’d for one; and is indeed, for the most part, made so sharp, that the naked eye cannot distinguish any parts of it: It very easily pierces, and makes its way through all kind of bodies softer then it self: But if view’d with a very good _Microscope_, we may find that the _top_ of a Needle (though as to the sense very _sharp_) appears a _broad_, _blunt_, and very _irregular_ end; not resembling a Cone, as is imagin’d, but onely a piece of a tapering body, with a great part of the top remov’d, or deficient. The Points of Pins are yet more blunt, and the Points of the most curious Mathematical Instruments do very seldome arrive at so great a sharpness; how much therefore can be built upon demonstrations made onely by the productions of the Ruler and Compasses, he will be better able to consider that shall but view those _points_ and _lines_ with a _Microscope_.

Now though this point be commonly accounted the sharpest (whence when we would express the sharpness of a point the most _superlatively_, we say, As sharp as a Needle) yet the _Microscope_ can afford us hundreds of Instances of Points many thousand times sharper: such as those of the _hairs_, and _bristles_, and _claws_ of multitudes of _Insects_; the _thorns_, or _crooks_, or _hairs_ of _leaves_, and other small vegetables; nay, the ends of the _stiriæ_ or small _parallelipipeds_ of _Amianthus_, and _alumen plumosum_; of many of which, though the Points are so sharp as not to be visible, though view’d with a _Microscope_ (which magnifies the Object, in bulk, above a million of times) yet I doubt not, but were we able _practically_ to make _Microscopes_ according to the _theory_ of them, we might find hills, and dales, and pores, and a sufficient bredth, or expansion, to give all those parts elbow-room, even in the blunt top of the very Point of any of these so very sharp bodies. For certainly the _quantity_ or extension of any body may be _Divisible in infinitum_, though perhaps not the _matter_.

But to proceed: The Image we have here exhibited in the first Figure[1], was the top of a small and very sharp Needle, whose point _aa_ nevertheless appear’d through the _Microscope_ above a quarter of an inch broad, not round nor flat, but _irregular_ and _uneven_; so that it seem’d to have been big enough to have afforded a hundred armed Mites room enough to be rang’d by each other without endangering the breaking one anothers necks, by being thrust off on either side. The surface of which, though appearing to the naked eye very smooth, could not nevertheless hide a multitude of holes and scratches and ruggednesses from being discover’d by the _Microscope_ to invest it, several of which inequalities (as A, B, C, seem’d _holes_ made by some small specks of _Rust_; and D some _adventitious body_, that stuck very close to it) were _casual_. All the rest that roughen the surface, were onely so many marks of the rudeness and bungling of _Art_. So unaccurate is it, in all its productions, even in those which seem most neat, that if examin’d with an organ more acute then that by which they were made, the more we see of their _shape_, the less appearance will there be of their _beauty_: whereas in the works of _Nature_, the deepest Discoveries shew us the greatest Excellencies. An evident Argument, that he that was the Author of all these things, was no other then _Omnipotent_; being able to include as great a variety of parts and contrivances in the yet smallest Discernable Point, as in those vaster bodies (which comparatively are called also Points) such as the _Earth_, _Sun_, or _Planets_. Nor need it seem strange that the Earth it self may be by an _Analogie_ call’d a Physical Point: For as its body, though now so near us as to fill our eys and fancies with a sense of the vastness of it, may by a little Distance, and some convenient _Diminishing_ Glasses, be made vanish into a scarce visible Speck, or Point (as I have often try’d on the _Moon_, and (when not too bright) on the _Sun_ it self.) So, could a Mechanical contrivance succesfully answer our _Theory_, we might see the least spot as big as the Earth it self; and Discover, as _Des Cartes_[2] also conjectures, as great a variety of bodies in the _Moon_, or _Planets_, as in the _Earth_.

But leaving these Discoveries to future Industries, we shall proceed to add one Observation more of a _point_ commonly so call’d, that is, the mark of a _full stop_, or _period_. And for this purpose I observed many both _printed_ ones and _written_; and among multitudes I found _few_ of them more _round_ or _regular_ then this which I have delineated in the third figure of the second Scheme, but _very many_ abundantly _more disfigur’d_; and for the most part if they seem’d equally round to the eye, I found those points that had been made by a _Copper-plate_, and Roll-press, to be as misshapen as those which had been made with _Types_, the most curious and smothly _engraven strokes_ and _points_, looking but as so many _furrows_ and _holes_, and their _printed impressions_, but like _smutty daubings_ on a matt or uneven floor with a blunt extinguisht brand or stick’s end. And as for _points_ made with a _pen_ they were much _more ragged_ and _deformed_. Nay, having view’d certain pieces of exceeding curious writing of the kind (one of which in the bredth of a _two-pence_ compris’d _the Lords prayer, the Apostles Creed, the ten Commandments, and about half a dozen verses besides of the Bible_, whose _lines_ were _so small_ and _near together_, that I was unable to _number_ them with my _naked eye_,) a very ordinary _Microscope_, I had then about me, inabled me to see that what the Writer of it had asserted was _true_, but withall discover’d of what pitifull _bungling scribbles_ and _scrawls_ it was compos’d, _Arabian_ and _China characters_ being almost as well shap’d, yet thus much I must say for the Man, that it was for the most part _legible_ enough, though in some places there wanted a good _fantsy_ well _preposest_ to help one through. If this manner _of small writing_ were made _easie_ and _practicable_ (and I think I know such a one, but have never yet made tryal of it, whereby one might be inabled to write _a great deale_ with _much ease_, and _accurately_ enough in a very _little roome_) it might be of very good use to convey _secret Intelligence_ without any danger of _Discovery_ or _mistrusting_. But to come again to the point. The _Irregularities_ of it are caused by three or four _coadjutors_, one of which is, the _uneven surface_ of the _paper_, which at best appears no smother then a very course piece of _shag’d cloth_, next the _irregularity of the Type_ or _Ingraving_, and a third is the _rough Daubing_ of the _Printing-Ink_ that lies upon the instrument that makes the impression, to all which, add the _variation_ made by the Different _lights_ and _shadows_, and you may have sufficient reason to ghess that a _point_ may appear much more _ugly_ then _this_, which I have here presented, which though it appear’d through the _Microscope_ _gray_, like a great splatch of _London_ dirt, about three inches over; yet to the _naked eye_ it was _black_ and no bigger then that in the midst of the Circle A. And could I have found Room in this Plate to have inserted an O you should have seen that the _letters_ were not more distinct then the _points_ of Distinction, nor a _drawn circle_ more exactly _so_, then we have now shown a _point_ to be a _point_.

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Observ. II. _Of the Edge of a Razor._

The sharpest _Edge_ hath the same kind of affinity to the sharpest _Point_ in Physicks, as a _line_ hath to a _point_ in Mathematicks; and therefore the Treaty concerning this, may very properly be annexed to the former. A Razor doth appear to be a Body of a very neat and curious aspect, till more closely viewed by the _Microscope_, and there we may observe its very Edge to be of all kind of shapes, except what it should be. For examining that of a very sharp one, I could not find that any part of it had any thing of sharpness in it; but it appeared a rough surface of a very considerable bredth from side to side, the narrowest part not seeming thinner then the back of a pretty thick Knife. Nor is’t likely that it should appear any otherwise, since as we just now shew’d that a _point_ appear’d a _circle_, ’tis rational a _line_ should be a _parallelogram_.

Now for the drawing this second Figure[3] (which represents a part of the Edge about half a quarter of an inch long of a Razor well set) I so plac’d it between the Object-glass & the light, that there appear’d a reflection from the very Edge, represented by the white line abcdef. In which you may perceive it to be somewhat sharper then elsewhere about d, to be indented or pitted about b, to be broader and thicker about c, and unequal and rugged about e, and pretty even between ab and ef. Nor was that part of the Edge ghik so smooth as one would imagine so smooth bodies as a Hone and Oyl should leave it; for besides those multitudes of scratches, which appear to have raz’d the surface ghik, and to cross each other every way which are not half of them exprest in the Figure, there were several great and deep scratches, or furrows, such as gh and ik, which made the surface yet more rugged, caus’d perhaps by some small Dust casually falling on the Hone, or some harder or more flinty part of the Hone it self. The other part of the Razor ll, which is polish’d on a grinding-stone, appear’d much rougher then the other, looking almost like a plow’d field, with many parallels, ridges, and furrows, and a cloddy, as ’twere, or an uneven surface: nor shall we wonder at the roughnesses of those surfaces, since even in the most curious wrought Glasses for _Microscopes_, and other Optical uses, I have, when the Sun has shone well on them, discover’d their surface to be variously raz’d or scratched, and to consist of an infinite of small broken surfaces, which reflect the light of very various and differing colours. And indeed it seems impossible by Art to cut the surface of any hard and brittle body smooth, since _Putte_, or even the most curious _Powder_ that can be made use of, to polish such a body, must consist of little hard rough particles, and each of them must cut its way, and consequently leave some kind of gutter or furrow behind it. And though Nature does seem to do it very readily in all kinds of fluid bodies, yet perhaps future observators may discover even these also rugged; it being very probable, as I elsewhere shew, that fluid bodies are made up of small solid particles variously and strongly mov’d, and may find reason to think there is scarce a surface _in rerum naturâ_ perfectly smooth. The black spot mn, I ghess to be some small speck of rust, for that I have oft observ’d to be the manner of the working of Corrosive Juyces. To conclude, this Edge and piece of a Razor, if it had been really such as it appear’d through the _Microscope_, would scarcely have serv’d to cleave wood, much less to have cut off the hair of beards, unless it were after the manner that _Lucian_ merrily relates _Charon_ to have made use of, when with a Carpenters Axe he chop’d off the beard of a sage Philosopher, whose gravity he very cautiously fear’d would indanger the oversetting of his Wherry.

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Observ. III. _Of fine Lawn, or Linnen Cloth._

This is another product of Art, A piece of the finest Lawn I was able to get, so curious that the threads were scarce discernable by the naked eye, and yet through an ordinary _Microscope_ you may perceive[4] what a goodly piece of _coarse Matting_ it is; what proportionable cords each of its threads are, being not unlike, both in shape and size, the bigger and coarser kind of _single Rope-yarn_, wherewith they usually make _Cables_. That which makes the Lawn so transparent, is by the _Microscope_, nay by the naked eye, if attentively viewed, plainly enough evidenced to be the multitude of square holes which are left between the threads, appearing to have much more hole in respect of the intercurrent parts then is for the most part left in a _lattice-window_, which it does a little resemble, onely the crossing parts are round and not flat.

These threads that compose this fine contexture, though they are as small as those that constitute the finer sorts of Silks, have notwithstanding nothing of their glossie, pleasant, and lively reflection. Nay, I have been informed both by the Inventor himself, and several other eye-witnesses, that though the flax, out of which it is made, has been (by a singular art, of that excellent Person, and Noble Virtuoso, M. _Charls Howard_, brother to the _Duke of Norfolk_) so curiously dress’d and prepar’d, as to appear both to the eye and the touch, full as _fine_ and as _glossie_, and to receive all kinds of colours, as well as Sleave-Silk; yet when this Silken Flax is twisted into threads, it quite loseth its former luster, and becomes as plain and base a thread to look on, as one of the same bigness, made of common Flax.

The reason of which odd _Phenomenon_ seems no other then this; that though the curiously drest Flax has its parts so exceedingly small, as to equallize, if not to be much smaller then the clew of the Silk-worm, especially in thinness, yet the differences between the figures of the constituting filaments are so great, and their substances so various, that whereas those of the _Silk_ are _small_, _round_, _hard_, _transparent_, and to their bigness proportionably _stiff_, so as each filament preserves its proper _Figure_, and consequently its vivid _reflection_ intire, though twisted into a thread, if not too hard; those of Flax are _flat_, _limber_, _softer_, and _less transparent_, and in twisting into a thread they joyn, and lie so close together, as to lose their own, and destroy each others particular reflections. There seems therefore three Particulars very requisite to make the so drest Flax appear Silk also when spun into threads. First, that the substance of it should be made more _clear_ and _transparent_, Flax retaining in it a kind of opacating brown, or yellow; and the parts of the whitest kind I have yet observ’d with the _Microscope_ appearing white, like flaw’d Horn or Glass, rather then clear, like clear Horn or Glass. Next that, the filaments should each of them be _rounded_, if that could be done, which yet is not so very necessary, if the first be perform’d, and this third, which is, that each of the small filaments be _stifned_; for though they be square, or flat, provided they be _transparent_ and stiff, much the same appearances must necessarily follow. Now, though I have not yet made trial, yet I doubt not, but that both these proprieties may be also induc’d upon the Flax, and perhaps too by one and the same Expedient, which some trials may quickly inform any ingenious attempter of, who from the use and profit of such an Invention, may find sufficient argument to be prompted to such Inquiries. As for the _tenacity_ of the substance of Flax, out of which the thread is made, it seems much inferiour to that of Silk, the one being a _vegetable_, the other an _animal_ substance. And whether it proceed from the better concoction, or the more homogeneous constitution of _animal_ substances above those of _vegetables_, I do not here determine; yet since I generally find, that _vegetable_ substances do not equalize the _tenacity_ of _animal_, nor these the _tenacity_ of some purified _mineral_ substances; I am very apt to think, that the _tenacity_ of bodies does not proceed from the _hamous_, or _hooked_ particles, as the _Epicureans_ and some modern _Philosophers_ have imagin’d; but from the more exact _congruity_ of the constituent parts, which are contiguous to each other, and so bulky, as not to be easily separated, or shatter’d, by any small pulls or concussion of heat.

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Observ. IV. _Of fine waled Silk, or Taffety._

This[5] is the appearance of a piece of very fine Taffety-riband in the bigger magnifying Glass, which you see exhibits it like a very convenient substance to make Bed-matts, or Door-matts of, or to serve for Beehives, Corn-scuttles, Chairs, or Corn-tubs, it being not unlike that kind of work, wherewith in many parts in _England_, they make such Utensils of Straw, a little wreathed, and bound together with thongs of Brambles. For in this Contexture, each little filament, fiber, or clew of the Silk-worm, seem’d about the bigness of an ordinary Straw, as appears by the little irregular pieces, ab, cd, and ef; The _Warp_, or the thread that ran crossing the Riband, appear’d like a single Rope of an Inch Diameter; but the _Woof_, or the thread that ran the length of the Riband, appear’d not half so big. Each Inch of six-peny-broad Riband appearing no less then a piece of Matting Inch and half thick, and twelve foot square, a few yards of this, would be enough to floor the long Gallery of the _Loure_ at _Paris_. But to return to our piece of Riband: It affords us a not unpleasant object, appearing like a bundle, or wreath, of very clear and transparent _Cylinders_, if the Silk be white, and curiously ting’d; if it be colour’d, each of those small horney _Cylinders_ affording in some place or other of them, as vivid a reflection, as if it had been sent from a _Cylinder_ of Glass or Horn. Insomuch, that the reflections of Red, appear’d as if coming from so many _Granates_, or _Rubies_. The loveliness of the colours of Silks above those of hairy Stuffs, or Linnen, consisting, as I else-where intimate, chiefly in the transparency, and vivid reflections from the _Concave_, or inner surface of the _transparent Cylinder_, as are also the colours of Precious Stones; for most of the reflections from each of these _Cylinders_, come from the _Concave_ surface of the air, which is as ’twere the foil that incompasses the _Cylinder_. The colours with which each of these _Cylinders_ are ting’d, seem partly to be superficial, and sticking to the out-sides of them; and partly, to be imbib’d, or sunck into the substance of them: for Silk, seeming to be little else then a dried thread of Glew, may be suppos’d to be very easily relaxt, and softened, by being steeped in warm, nay in cold, if penetrant, juyces or liquors. And thereby those tinctures, though they tinge perhaps but a small part of the substance, yet being so highly impregnated with the colour, as to be almost black with it, may leave an impression strong enough to exhibite the desir’d colour. A pretty kinde of artificial Stuff I have seen, looking almost like transparent Parchment, Horn, or Ising-glass, and perhaps some such thing it may be made of, which being transparent, and of a glutinous nature, and easily mollified by keeping in water, as I found upon trial, had imbib’d, and did remain ting’d with a great variety of very vivid colours, and to the naked eye, it look’d very like the substance of the Silk. And I have often thought, that probably there might be a way found out, to make an artificial glutinous composition, much resembling, if not full as good, nay better, then that Excrement, or whatever other substance it be out of which, the Silk-worm wire-draws his clew. If such a composition were found, it were certainly an easie matter to find very quick ways of drawing it out into small wires for use. I need not mention the use of such an Invention, nor the benefit that is likely to accrue to the finder, they being sufficiently obvious. This hint therefore, may, I hope, give some Ingenious inquisitive Person an occasion of making some trials, which if successfull, I have my aim, and I suppose he will have no occasion to be displeas’d.

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Observ. V. _Of watered Silks, or Stuffs._

There are but few _Artificial_ things that are worth observing with a _Microscope_, and therefore I shall speak but briefly concerning them. For the Productions of art are such rude mis-shapen things, that when view’d with a _Microscope_, is little else observable, but their deformity. The most curious Carvings appearing no better then those rude _Russian_ Images we find mention’d in _Purchas_, where three notches at the end of a Stick, stood for a face. And the most smooth and burnish’d surfaces appear most rough and unpolisht: So that my first Reason why I shall add but a few observations of them, is, their mis-shapen form; and the next, is their uselessness. For why should we trouble our selves in the examination of that form or shape (which is all we are able to reach with a _Microscope_) which we know was design’d for no higher a use, then what we were able to view with our naked eye? Why should we endeavour to discover mysteries in that which has no such thing in it? And like _Rabbins_ find out _Caballisms_, and _ænigmâs_ in the Figure, and placing of Letters, where no such thing lies hid: whereas in _natural_ forms there are some so small, and so curious, and their design’d business so far remov’d beyond the reach of our sight, that the more we magnify the object, the more excellencies and mysteries do appear; And the more we discover the imperfections of our senses; and the Omnipotency and Infinite perfections of the great Creatour. I shall therefore onely add one or two Observations more _artificial_ things, and then come to the Treaty concerning such matters as are the Productions of a more curious Workman. One of these, shall be that of a piece of water’d Silk, represented in the second Figure of the third _Scheme_,[6] as it appear’d through the least magnifying Glass. _AB_ signifying the long way of the Stuff, and _CD_ the broad way. This Stuff, if the right side of it be looked upon, appears to the naked eye, all over so waved, undulated, or grain’d, with a curious, though irregular variety of brighter and darker parts, that it adds no small gracefulness to the Gloss of it. It is so known a propriety, that it needs but little explication, but it is observable, which perhaps everyone has not considered, that those parts which appear the darker part of the wave, in one position to the light, in another appears the lighter, and the contrary; and by this means the undulations become transient, and in a continual change, according as the position of the parts in respect of the incident beams of light is varied. The reason of which odd _phænomena_, to one that has but diligently examin’d it even with his naked eye, will be obvious enough. But he that observes it with a _Microscope_, may more easily perceive what this _Proteus_ is, and how it comes to change its shape. He may very easily perceive, that it proceeds onely from the variety of the _Reflections_ of light, which is caus’d by the various _shape of the Particles_, or little protuberant parts of the thread that compose the surface; and that those parts of the waves that appear the brighter, throw towards the eye a multitude of small reflections of light, whereas the darker scarce afford any. The reason of which reflection, the _Microscope_ plainly discovers, as appears by the Figure. In which you may perceive, that the brighter parts of the surface consist of an abundance of large and strong reflections, denoted by a, a, a, a, a, &c. for the surfaces of those threads that run the _long way_, are by the Mechanical process of watering, _creas’d_ or _angled_ in another kind of posture then they were by the weaving: for by the weaving they are onely _bent round_ the warping threads; but by the watering, they are _bent with an angle, or elbow_, that is in stead of lying, or being bent _round_ the threads, as in the third Figure, a, a, a, a, a, are about b, b, b (b, b, b representing the ends, as ’twere, of the cross threads, they are bent about) they are creas’d on the top of those threads, with an _angle_, as in the fourth Figure, and that with all imaginable variety; so that, whereas before they reflected the light onely from one point of the round surface, as about c, c, c, they now when water’d, reflect the beams from more then half the whole surface, as de, de, de, and in other postures they return no reflections at all from those surfaces. Hence in one posture they compose the brighter parts of the waves, in another the darker. And these reflections are also varied, according as the particular parts are variously bent. The reason of which creasing we shall next examine; and here we must fetch our information from the Mechanism or manner of proceeding in this operation; which, as I have been inform’d, is no other then this.