Having now retrieved a little more of leasure, both for Delineation and Description, for a further elucidation of what I have said, I shall make it my third Attempt, to explain;
First, A Helioscope to look upon the body of the Sun, without any offence to the Observers eye.
Secondly, A way of shortening reflective and refractive Telescopes.
Thirdly, A way of using a Glass of any length, without moving the Tube.
Fourthly, An Instrument for taking the Diameters of the Sun, Moon and Planets, or for taking any other Distances, to five or ten Degrees, to the certainty of a Second. ...
Fifthly, An Instrument for describing all manner of Dials, by the tangent projection.
Sixthly, The uses thereof;
1. For adjusting the Hand of a Clock, so as to make it move in the shadow of a Dial, whose style is parallel to the Axis: Or,
2. In the Azimuth of any Celestial Body, that is, in the shadow of the upright, or any other way inclining Style, upon any plain.
3. For making a Hand move according to the true æquation of Time.
4. For making all manner of Elliptical Dials, in Mr. Foster's way, &c.
5. For communicating a circular motion in a Curve Line, without any shaking: And for divers other excellent purposes.
English natural philosopher, architect and polymath (1635 — 1703)
Robert Hooke (July 18, 1635 – March 3, 1703) was an English polymath, to include inventor, microscopist, architect, surveyor, professor of geometry, natural philosopher and chemist. He was the first Curator of Experiments for the and is noted for Hooke's law, his contributions to the development of the vacuum pump, the improved accuracy of the portable watch through the invention of the balance spring, for his microscopy, as author and illustrator of Micrographia, being the first to use the term cell, and as Surveyor to the City of London and chief assistant to Christopher Wren, in the reconstruction efforts following the Great Fire of London.
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By the means of Telescopes, there is nothing so far distant but may be represented to our view; and by the help of Microscopes, there is nothing so small, as to escape our inquiry; hence there is a new visible World discovered to the understanding. By this means the Heavens are open’d, and a vast number of new Stars, and new Motions, and new Productions appear in them, to which all the ancient Astronomers were utterly Strangers.
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The Reason of the present Animadversions. ...How far Hevelius has proceeded. That his instruments do not much exceed Ticho. The bigness, Sights and Divisions, not considerably differing. Ticho not ignorant of his new way of Division. ...
That so great curiosity as Hevelius strives for is needless without the use of Telescopic Sights, the power of the naked eye being limited. That no one part of an Instrument should be more perfect than another. ...
That if Hevelius could have been prevail'd on by the Author to have used Telescopic Sights, his observations might have been 40 times more exact than they are.
That Hevelius his Objections against Telescopic sights are of no validity; but the Sights without Telescopes cannot distinguish a less angle then half a Minute.
That an Instrument of 3 foot Radius with Telescopes, will do more then one of 3 score foot Radius with common Sights, the eye being unable to distinguish. This is proved by the undiscernableness of spots in the Moon, and by an Experiment with Lines on a paper, by which a Standard is made of the power of the eye. ...
A Conclusion of the Animadversions. That the learn'd World is obllig'd to Hevelius for what he hath done, but would have more, if he had used other instruments.
That the Animadvertor both contrived some hundreds of Instruments, each of very great accurateness for taking Angles, Levels, &c. and a particular Arithmetical lnstrument for performing all Operations in Arithmetick, with the greatest ease, swiftness and certainty imaginable.
That the Reader may be the more certain of this, the Author describes an Instrument for taking Angles in the Heavens...
The true Mathematical and Mechanical Form of all manner of Arches for building with the true butment necessary to each of them, a Problem which no Architectonick Writer hath ever yet attempted, much less perform'd. ...Ut pendet continaum flexile, sic stabit contiguum rigidum, which is the Linea Catenaria.
I should here have described some Clocks and Time-keepers of great use, nay absolute necessity in these and many other Astronomical observations, but that I reserve them for some attempts that are hereafter to follow, about the various wayes I have tryed, not without good success of improving Clocks and Watches and adapting them for various uses, as for accurating Astronomy, completing the Tables of the fixt stars to Seconds, discovery of Longitude, regulating Navigation and Geography, detecting the properties and effects of motions for promoting secret and swift conveyance and correspondence, and many other considerable scrutinies of nature: And shall only for the present hint that I have in some of my foregoing observations discovered some new Motions even in the Earth it self, which perhaps were not dreamt of before, which I shall hereafter more at large describe, when further tryalls have more fully confirmed and compleated these beginnings. At which time also I shall explaine a Systeme of the World, differing in many particulars from any yet known, answering in all things to the common Rules of Mechanicall Motions: This depends upon three Suppositions. First, that all Cœlestial Bodies whatsoever, have an attraction or gravitating power towards their own Centers, whereby they attract not only their own parts, and keep them, from flying from them, as we may observe the Earth to do, but that they do also attract all the other Cœlestial Bodies that are within the sphere of their activity; and consequently that not only the Sun and the Moon have an influence upon the body and motion of the Earth, and the Earth upon them, but that Mercury also, Venus, Mars, Saturne, and Jupiter by their attractive powers, have a considerable influence upon its motion as in the same manner the corresponding attractive power of the Earth hath a considerable influence upon every one of their motions also. The second supposition is this, That all bodys whatsoever that are put into direct and simple motion, will so continue to move forward in a streight line, till they are by some other effectual powers deflected and bent into a Motion describing a Circle, Ellipsis, or some other more compounded Curve Line. The third supposition is, That these attractive powers are so much the more powerful in operating, by how much nearer the body wrought upon is to their own Centers. Now what these several degrees are I have not yet experimentally verified;—But these degrees and proportions of the power of attraction in the celestiall bodys and motions, were communicated to Mr. Newton by R. Hooke in the yeare 1678, by letters, as will plainely appear both by the coppys of the said letters, and the letters of Mr. Newton in answer to them, which are both in the custody of the said R. H., both which also were read before the Royall Society at their publique meeting, as appears by the Journall book of the said Society.—but it is a notion which if fully prosecuted as it ought to be, will mightily assist the astronomer to reduce all the Cœlestiall motions to a certaine rule, which I doubt will never be done true without it. He that understands the natures of the Circular Pendulum and Circular Motion, will easily understand the whole ground of this Principle, and will know where to find direction in nature for the true stating thereof. This I only hint at present to such as have ability and opportunity of prosecuting this Inquiry, and are not wanting of Industry for observing and calculating, wishing heartily such may be found, having my self many other things in hand which I would first compleat, and therefore cannot so well attend it. But this I durst promise the Undertaker, that he will find all the great Motions of the World to be influenced by this Principle, and that the true understanding thereof will be the true perfection of Astronomy.
About this time, 1655, having an opportunity of acquainting myself with astronomy by the kindness of Dr. Ward, I apply'd myself to the improving of the pendulum for such observations, and in the year 1656, or 1657, I contriv'd a way to continue the motion of the pendulum, so much commended by Ricciolus in his Almagestum which Dr. Ward had recommended to me to peruse. I made some trials to this end, which I found to succeed to my wish. The success of these made me further think of improving it for finding the longitude; and the method I had made for myself for mechanick inventions, quickly led me to the use of springs, instead of gravity, for the making a body vibrate in any posture. Whereupon I did first in great, and afterwards in smaller modules, satisfy myself of the practicableness of such an invention; and hoping to have made great advantage thereby, I acquainted divers of my freinds, and particularly Mr. Boyle, that I was possessed of such an invention, and crav'd their assistance for improving the use of it to my advantage. Immediately after his majesty's restoration Mr. Boyle was pleased to acquaint the lord Brouncher and Sir with it, who advis'd me to get a patent for the invention, and propounded very probable ways of making considerable advantage by it. To induce them to a belief of my performance, I shewed a pocket watch, accommodated with a spring, apply'd to the arbor of the ballance, to regulate the motion thereof, concealing the way I had for finding the longitude. This was so well approv'd of, that Sir Robert Moray drew me up the form of a patent, the principal part whereof, viz. the description of the watch so regulated, is his own hand writing, which I have yet by me. The discouragement I met with in the management of this affair, made me desist for that time.
Some other Course therefore must be taken to promote the Search of Knowledge. Some other kind of Art for Inquiry than what hath been hitherto made use of, must be discovered; the Intellect is not to he suffer'd to act without its Helps, but is continually to be assisted by some Method or Engine, which shall be as a Guide to regulate its Actions, so as that it shall not be able to act amiss: Of this Engine, no Man except the incomparable Verulam hath had any Thoughts, and he indeed hath promoted it to a very good pitch; but there is yet somewhat more to be added, which he seem'd to want time to compleat. By this, as by that Art of Algebra in Geometry, 'twill be very easy to proceed in any Natural Inquiry, regularly and certainly: And indeed it may not improperly be call'd a Philosophical Algebra, or an Art of directing the Mind in the search after Philosophical Truths, for as 'tis very hard for the most acute Wit to find out any difficult Problem in Geometry. without the help of Algebra to direct and regulate the Acts of the Reason in the Process from the question to the quœsitum, and altogether as easy for the meanest Capacity acting by that Method to compleat and perfect it, so will it be in the inquiry after Natural Knowledge.
Nor is this kind of Texture peculiar to Cork onely; for upon examination with my Microscope, I have found that the pith of an Elder, or almost any other Tree, the inner pulp or pith of the Cany hollow stalks of several other Vegetables: as of Fennel, Carrets, Daucus, Bur-docks, Teasels, Fearn, some kinds of Reeds &c., have much such a kind of Schematisme, as I have lately shewn that of Cork, save onely that here the pores are rang'd the long-ways, or the same ways with the length of the Cane, whereas in Cork they are transverse.
The pith also that fills that part of the stalk of a Feather that is above the Quil, has much such a kind of texture, save onely that which way foever I set this light substance, the pores seem'd to be cut transversly, so that I guess this pith which fills the Feather, not to consist of abundance of long pores separated with Diaphragms, as Cork does, but to be a kind of solid or hardned froth, or a congeries of very small bubbles consolidated in that form, into a pretty stiff as well as tough concrete, and that each Cavern, Bubble, or Cell, is distinctly separate from any of the rest, without any kind of hole in the encompassing films, so that I could no more blow through a piece of this kinde of substance, then I could through a piece of Cork, or the found pith of an Elder.
The Publisher of Transactions in that of October 1675 indeavours to cover former injuries done me by accumulating new ones, and this with so much passion as with integrity to lay by discretion; otherwise he would not have affirmed, that it was as certain that none of my Watches succeeded, as it was that I had made them several years ago: For how could he be sure of a Negative? Whom I have not acquainted with my Inventions, since l looked on him as one that made a trade of Intelligence.
Next whereas he says l made them without publishing them to the world in Print, he prevaricates, and would have it believed that they were not published to the world, though they were publickly read of in Sir John Cutlers Lectures before great numbers at several times, and though they were made and shewn to thousands both English and Foreiners, and writ of to several persons absent, and though they were in the year 1665 in the History of the Royal Society published to the world in Print, because, forsooth, they were not printed in his Transactions.
Thirdly, whereas the Publisher of Transactions makes along story of my seeing his Journal De Scavans, and my desiring to transcribe that part of it which concerned this matter, as if l had requested some singular favour thereby, l answer,
First, that he knew I designed presently to have printed it with Animadversions, but he endeavoured to prevent me, designing first clancularly to get a Patent of it for himself, and thereby to defraud me.
Next, I say, I had a right without his favour to have seen, perused, and copied it, as I was one of the Royal Society, the intelligence he there brings in being the Societies. ...
To his upbraiding me with his having published some things of Mine; I answer, he hath so, but not so much with mine as with his own desire, and if he send me what I think worth publishing, l will do as much for him, and repay him in his own coyn.
Lastly, Whereas he makes use of We and Us ambiguously, it is desired he would explain whether he means the Royal Society, or the Pluralities of himself. If the former, it is not so, as l can prove by many Witnesses; if the later, I neither know what he is acquainted with, or what has been imparted or explained to him.
So not designing to trouble my self any further with him, unless he gives me occasion, I dismiss him with his
— Speque metuque
Procul hinc procul ito.
At these meetings, which were about the year 1655, divers experiments were suggested, discoursed, and tried with various successes, though no other account was taken of them but what particular persons perhaps did for the help of their own memories; so that many excellent things have been lost. Some few only by the kindness of the authors have since been made public. Among these may be reckoned the Honourable Mr Boyle's Pneumatic Engine and Experiments, first printed in the year 1660; for in 1658 or 1659 I continued and perfected the air-pump for Mr Boyle, having first seen a contrivance for that purpose made for the same honourable person by Mr Gratorix, which was too gross to perform any great matter.