When an Eye is armed with a Telescope: The Dioptrics of William and Samuel Molyneux. By Peter Abrahams. 'Tis manifest by Experiments, that the ordinary Power of Man's Eye extends no farther than perceiving what subtends an Angle of about a Minute, or something less. But when an Eye is armed with a Telescope, it may discern an Angle less than a Second.' Dioptrica Nova, page 243. William Molyneux was born in Dublin on 17 April 1656, and died in Dublin on 11 Oct. 1698, at age 42. He was among the fourth generation of Molyneuxs in Ireland, part of the Protestant ruling class, not assimilated but known as 'the English in Ireland'. Samuel Molyneux, father of Thomas and William Molyneux, was a wealthy property owner, held the office of Master-Gunner of Ireland, and maintained the rank of Mortar Gunner because he enjoyed the explosive experiments this permitted him. Thomas was a famous physician and public figure. William studied at Trinity College, Dublin, from 1671 until he received his Bachelor of Arts degree in 1675. He married Lucy Domvile in 1678, a lady noted for intelligence, amiability, and great beauty, but who fell ill months after the marriage, became blind, and lived in pain until her death in 1691. There were three children but only Samuel lived past childhood, to become an important astronomer. William had a hereditary problem with his kidneys which greatly interfered with his activities and caused his early death in 1698. His library at that time held about 2,000 books, almost all on science. Molyneux is interred in the north aisle of St. Audoen's Church, Dublin. A portrait of Molyneux, painted by Kneller, is in the examination hall, Trinity College, Dublin. Molyneux inherited sufficient wealth to allow him to devote his time to avocations, but superintendence of family property could require much attention; in particular, when Dioptrica Nova was underway, management of an estate in County Armagh that had been in a war zone was a pressing obligation. He purchased, for 250 pounds, one half of the appointment as Surveyor-General of the King’s Buildings, which paid him 150 pounds per year, serving from 1684 to 1688. After Molyneux secured the entire appointment, the restoration of fire-damaged Dublin Castle was his responsibility, and he supervised construction of the turreted portion on the south side of the open square. In 1685 he traveled to the Netherlands to survey their major fortresses. In 1690, he became Commissioner handling the accounts of the army in Ireland, with a salary of 500 pounds. Molyneux represented Dublin University in the Irish Parliament from 1692 to 1695. Molyneux was a member of the Royal Society, and in emulation became the major founding member of the Dublin Philosophical Society in 1684, also acting as its first secretary. About a dozen members would meet in a coffeehouse on Cock Hill, later meeting in homes, where they listened to papers and corresponded with other societies. Molyneux proposed that they jointly observe solar and lunar eclipses with societies in London (later Greenwich), and Oxford. The first of several was the solar eclipse of July 1684. The Dublin society was dispersed by a new government, resumed, and finally disbanded in 1708 after having a very beneficial effect on scientific life in the area. Dublin had a population of about 70,000 people and was the second largest city in the British Isles at this time. Molyneux owned many instruments in his career. He noted that in Dublin there was a shortage of 'ingenious artificers', which hindered his efforts. Although in 1660-1680 there were at minimum 17 clock makers in Dublin, instruments were scarce. Molyneux owned at least two telescopes, of 16 feet and 30 feet. With the assistance of Flamsteed, Molyneux began ordering instruments from London. In December 1681, he ordered a quadrant of two foot radius, with a telescopic sight, which was tested by Flamsteed, and returned to the maker for corrections before shipping to Dublin. These corrections were not properly done, and Molyneux unsuccessfully tried to use the quadrant to observe a comet in August 1682, depriving us of observations from Dublin of Halley's comet. The Flamsteed- Molyneux letters contain requests for the testing of a purchased telescope, observations on eclipses, criticism from Flamsteed on those observations, and much more. In a 1694 letter to his brother Thomas, Molyneux wrote regarding telescopes: "I had formerly some large astronomical ones, but these I parted with, intending to procure better; but the distractions of the times, and now, an infirm constitution in my health coming on me, I have desisted from prosecuting celestial observations, as exposing me too much to nocturnal colds, and other inconveniencys. The instruments therefore which I yet retain (besides the mechanick tools left by my father, and a few mathematical trifles I myself purchased) are chiefly dioptrical, such as glasses for telescopes of all lengths, from one foot to thirty feet, microscopes of all kinds, prismes, magick lantern, micrometers, pendulum clocks, &c." (Hoppen p94, http://indigo.ie/~kfinlay/Gilbert/gilbert9.htm ) Molyneux developed the 'Dublin Hygroscope' to measure moisture in the atmosphere, and published in Philosophical Transactions on that instrument. In 1683, Molyneux was the first person to demonstrate the circulation of blood in a living creature, by observing a newt under a microscope. "I have been often delighted with the curious Appearance of many Objects seen through the Microscope. But none ever surprised me more, than the visible Circulation of the Blood in Water-Newts (Lacerta aquatica) to be seen as plainly as Water running in a River, and proportionably much more rapid. (Dioptrica p281; Philosophical Transactions #177, p1236; Simms p40) Molyneux took part in the astronomical controversies of his day. Johannes Hevelius of Danzig used open sights on angle measuring instruments to determine celestial positions, and wrote in 'Machina Coelestis', 1673, that this technique was superior to the use of telescopic sights. Robert Hooke of London argumentatively disputed this claim in 'Animadversions On the first part of the Machina Coelestis', 1674. Molyneux criticized Hooke for the hostile nature of his criticism. Edmund Halley traveled to Danzig in 1679, carrying a quadrant with telescopic sights, to compare with Hevelius' instruments. Halley wrote a report on the high accuracy of Hevelius' work, noting that the open & telescopic sights were very close in function. In 1685, Hevelius published 'Annus Climactericus', reiterating his claim and including Halley's results, but mistakenly writing that Halley had used a more accurate sextant. Molyneux reviewed the book for the Dublin Philosophical Society and in a letter, showing in great detail that Halley's results using telescopic sights were significantly different than Hevelius' results, thus rendering questionable Halley's observations. The enhanced accuracy of telescopic sights was obvious to Molyneux, who translated his letter into Latin for sending to Hevelius, adding a correction that Halley had used a quadrant, which was inherently less accurate than the sextant described by Hevelius, thus negating any conclusions. European contacts were important to Molyneux. In 1684 his brother Thomas visited Christiaan Huygens in the Hague, seeing instruments and Huygen's method of constructing a tubeless telescope, also receiving a book on the telescope by Huygens ('Astroscopia...'). Thomas sent the book to William with a descriptive letter, who in turn discussed the book, letter, & method to the Dublin Philosophical Society. William Molyneux took a journey to Europe in the summer of 1685, first to The Hague, where Huygens showed him instruments and telescopes. In Delft, Leeuwenhoek displayed microscopes, but as usual not his very best examples (Thomas had the same experience with Leeuwenhoek.) Jean-Dominique Cassini at the Paris Observatory showed Molyneux his clock drive for a telescope and his method of testing lenses by reading a printed page set in a distant window. Pierre Borel of Paris, a physician and writer on telescopes and microscopes, presented Molyneux with a 24 foot telescope objective. The astronomical instruments used in France did not seem as useful as English instruments, Molyneux described them as smaller - of about half the radius as the English models, and not as developed. On the way home, Molyneux stopped in London for several weeks in September of 1685. He visited Flamsteed but inadvertently caused a problem when Edmund Halley accompanied him, since Flamsteed strongly disliked Halley. Molyneux's first publication was in 1680, a translation of Descartes, 'Six Metaphysical Meditations', including a biography and introduction. Many of Molyneux's articles appeared in the Philosophical Transactions of the Royal Society, on subjects including optics and other sciences, but very little on astronomy. Some manuscripts survive at Trinity College, Dublin. William Molyneux's major contribution to optics was his 300 page book, 'Dioptrica Nova, A treatise of dioptricks in two parts, wherein the various effects and appearances of spherick glasses, both convex and concave, single and combined, in telescopes and microscopes, together with their usefulness in many concerns of humane life, are explained'. This was the first English language optics book. Molyneux told his brother that his goal was to instruct, without the obscurities found in earlier books on dioptrics, and in particular to plainly show how useful the mathematics could be. (Simms p71). Due to fighting in Ireland during 1689-1690, when Dioptrica was written, Molyneux was in exile in Chester, England. It was published in London in 1692, and the advertisement on the rear end page is for optical instruments by John Yarwell of London. He began writing the book in Latin but switched to English because no similar work had been written in English, and many skilled workers knew no Latin. "I am sure there are many ingenious Heads, great Geometers, and masters in Mathematics, who are not so well skill’d in Latin." (Admonition to the Reader) The lengthy dedication to the first part of Dioptrica was to the Royal Society, for establishing the place of experiment over the Aristotlelian dogma of the time. "The commentators on Aristotle....have rendred Physicks an heap of froathy Disputes....by Hypothetical Conjectures, confirmed by plausible Arguments of Wit and Rhetorick....But never studied to prove their Opinions by Experiments....these were the great Dictators of Physics." (Dedication) The first 190 pages of Dioptrica Nova consist of 59 propositions followed by scholiums and corollaries, the proof of each proposition based on the earlier proofs. One proposition is on vision, two are on microscopes, and 56 are on telescope optics. It is rather tedious reading, though if the reader were mathematically skilled and faced with the decision about whether to use 3 or 4 lenses in an erecting eyepiece, Dioptrica would be a useful book. This is not an entirely arid text, Proposition 28, on vision, includes on p105, "the Representation of the Object....on the Fund of the Eye...is Inverted.....How then it comes to pass that the Eye sees the Object Erect?....'tis not properly the Eye that sees, it is only the Organ or Instrument, 'tis the Soul that sees by the means of the Eye....the Soul perceives the Object Erect...to enquire into the Soul's Faculties is not the proper subject of this Discourse." Here Molyneux has clearly been derailed from his experimentalist platform. However, most of the first part is aridly characterized by a chapter that is a reprint of an earlier Molyneux contribution to Philosophical Transactions #183: 'A Dioptrick Problem, Why four Convex-glasses in a Telescope, shew Objects Erect'. This is a chapter that surpasses monotony, in attempting to explain verbally the possibilities of image inversion and erection in lens systems; but it is worth noting as an example of the problems dealt with by designers in the first century of the telescope. Molyneux explains, in a lengthy fashion, that a single convex lens inverts the image, the second acts as an eyepiece and does not revert the image, the third erects the image in a second inversion, and the fourth acts as an eyepiece and brings the image out without inversion. The distinct actions are due to placing the lens inside or outside focus. This formulaic portion of Dioptrica was an original text, but it included the work of Leibniz, Halley, and Flamsteed. Gottfried Leibniz had published a refutation of Descartes theory of refraction, and this was included in Dioptrica. (In 1682, Molyneux had published a partial translation of Leibniz' article 'Unicum opticae catoptricae et dioptricae principium'.) Edmund Halley provided significant corrections to a draft of Dioptrica, and the book included as an appendix the first printing of Halley's important equation for the foci of spherical lenses. Halley supervised the publication of 'Dioptrica' when Molyneux returned to Ireland in 1691. John Flamsteed in particular was the source of important portions of 'Dioptrica'. While in Dublin, Molyneux had been unable to find assistance in learning optics, and was taught by Halley, but especially was taught by Flamsteed, who was a willing and patient teacher. Significant portions of Dioptrica are based on the work of Flamsteed, who in turn credited his knowledge of optics to William Gascoigne, who was killed in war at a young age but left behind papers that were used by Flamsteed. When Dioptrica was written in 1689-1690, Molyneux included a note that his description of a geometrical method of ray calculation had never before been published, and was owed to Flamsteed, who had learned it from the papers of Gascoigne. In a letter to Molyneux from 1686, Flamsteed wrote that he was writing a book on optics, to include his earlier tutorial letters about lens combinations in telescopes, and that therefore those letters were to be kept private; to which Molyneux replied in agreement. After Molyneux's book was finished, he wrote to Flamsteed, told him about the book, and requested permission to include the ideas that Flamsteed had earlier written. This permission was granted, adding that the publication would free Flamsteed from "some fools who are frequently pressing me to give those dioptric propositions, and an account of the telescope, and the effect of compounded glass." (Simms p65) Propositions 16, 17, and 18 of 'Dioptrica' are followed by the solutions of Flamsteed, with acknowledgement. Flamsteed had taught optics to Molyneux, and his solutions were presented as a supplement, which offended Flamsteed, who proceeded to tell others of errors in the text and, according to Molyneux, generally behave like 'a man of so much ill-nature and irreligion' (Hoppen p128). Their long standing friendship ended with Dioptrica. The second part of Dioptrica is dedicated to Henry Osborne of Dardys-Town, County Meath, an astronomer who owned a telescope, micrometer, and quadrant with telescopic sights. The two corresponded on optical subjects, and after the solar eclipse of July 1684, Osborne's observations were sent by Molyneux to be published in 'Philosophical Transactions'. Part Two, titled 'Containing Various Dioptrick Mescellanies', opens with a note that there is no English language description of optical fabrication, grinding, polishing, tooling or machinery. Readers who are fluent in other languages are referred to Cherubin d'Orleans, 'Dioptrique Oculaire' or Johannes Zahn, 'Oculus Artificialis'. A very valuble portion of this book discusses the current literature on the subjects of optical fabrication and telescopes. This includes page 215, publications that discuss grinding machines: Robert Hooke, Micrographia; Hevelius, Selenographia Chapter 1 & 2 (making the forms for grinding glass); Hevelius, Machina Coelestis Chapter 23 (grinding conic glasses); Schyrleus de Rheita, Oculus Enoch et Eliae, Lib. 4 (conic glasses); Maignan, Perspectiva Horaria (end of book, spherical and conical glasses); Descartes, Dioptrics (conic glasses); Borelly, Journal des Scavans, Ann. 1676, July 6 (grinding 'great' glass, in cipher, not yet deciphered); Fatio de Duillier, Journal des Scavans, Ann. 1684, November 20 (making forms for grinding spherical glass); Christopher Wren ('our English Archimedes, Apollonius, Diophantus'), Philosophical Transactions #48 & 53 (hyperbolic glasses). The list continues on page 223 with: Huygens' small booklet, Astroscopia compendiaria tubi optici molimine liberata, The Hague, 1684, which describes his method of managing great glasses without a tube. Page 224, Cusset, of Lions, Journal des Scavans, Ann. 1685, May 18 (contrivance for managing great glasses). Page 225, Boffat of Tolouse, Journal des Scavans, 1682 Dec. 28, contrivance for managing great glasses, briefly described. In 'Dioptrica', Molyneux does not just list books, he reviews a few of them. On page 222, Molyneux critically notes "Pere Cherubin, who is often very nice in matters of little moment, and loose enough in those of greater weight and absolute necessity, describes an implicated contrivance for true centring of glasses, Vision Parfait, Tom. II, p109". On page 237, Cherubin's ideas about telescopic sights are described as 'deficient and useless'. However, Cherubin's procedures for testing glass on page 25 of Vision Parfait are described in detail by Molyneux, as are Cherubin's eyepiece configurations on pp222 & 226. Molyneux also cites Newton, "as great a philosopher and mathematician as this or any age could ever boast of", unfortunately Molyneux makes a point of an issue later found erroneous, in Prinicipia Mathematica, first book, scholium 98, where Newton writes that for optics, spherical figures are the best, that perhaps corrections could be made in an objective by using two lenses with water in between them, and that glass lenses of any figure will never be perfected optics. Molyneux continues by discussing prior art; how to find foci of lenses; and the importance of centration of lenses in great detail. He recommends testing a telescope by viewing a printed page set at a distance, as he saw Cassini do at the Paris Observatory. Molyneux visited Cassini and describes his "contrivances for managing great glasses" (p224), somewhat similar to Hooke's in 'Animadversions on Hevelius', p66-68. An interesting section is found on page 226. Molyneux discusses the 'proportioning of the glasses in telescopes and microscopes', by which he means the relationship between the focal lengths of the objective and the eyepiece. In comparing objectives of the same focal length, the glass of superior quality is that which can be used with an eyepiece of greatest convexity, meaning the smallest focal length. In the charming vernacular of the time, Molyneux describes shortest focus as 'the deepest charge'. A high quality object glass of 12 or 13 foot focus will 'bear a charge' of 3 inches (eyepiece) much better than a deeper charge or a shallower charge. (The earliest Italian name for a telescope was Cannocchiali, and there seems to be a carrying forward of the perceived resemblance of a telescope to an artillery piece.) Venus is regarded as an object 'of a more brisk and strong light', compared to Saturn and Jupiter, which are 'objects of a sedate light', and which will 'allow deeper charges', or higher power, presumably because Venus becomes swamped by color when magnified. Molyneux enters one of the more contentious debates of his time on page 228, where he repeats his claims that by advocating plain sights for instruments, Johannes Hevelius misunderstands the nature of telescopic sights. Several pages are spent in establishing that a telescope with a cross hair can have all parts properly aligned, and then describing how to collimate the optical axis of the instrument with the physical axis of the sight. When a cross hair is at the precise focus of the objective, the image of the cross and the image of the object will be immovable on each other, and will not 'seem to move or dance'. Molyneux continues, "This I have borrowed from my own 'Sciathericum Telescopicum'....And I hope, one may be allowed to transcribe from himself without being called a Plagiary" (p235). The rectification of telescopic sights on sextants and quadrants is then discussed. On page 245 he counters some objections: "Telescope-Sights are so far from being obnoxious.....'Tis true, the Breath of the Observer, if puft into the Telescope, will sully the Eye-Glass, but how easily is this avoided? Who is it goes purposely to make a Speaking-Trumpet of a Telescope?" (It is amusing to note that the advertisement for optical instruments by John Yarwell, on the rear end page of the book, includes telescopes, microscopes, magnifiers, spectacles, speaking trumpets, and all other sorts of glasses.) It is on page 243, in the section on telescopic sights, that Molyneux writes, (in 1692) an immortal phrase in the annals of telescopy: "I come now to the last thing proposed concerning Telescopick-Sights; and that is, To shew the Dioptrick- Reason of their Performance and Exactness.....'Tis manifest by Experiments, that the ordinary Power of Man's Eye extends no farther than perceiving what subtends an Angle of about a Minute, or something less. But when an Eye is armed with a Telescope, it may discern an Angle less than a Second. The Telescope that magnifies distinctly the Appearance of a Body, magnifies also distinctly the Appearance of Extension, Space, and Motion through this Space; so if the Minute- Hand of a Watch, which can but just be perceived to move, be looked upon with a Magnifying-Glass, we shall see it give a considerable Leap at every Stroak of the Balance. And thus likewise the slow diurnal Motion of the Sun or Stars, which is hardly perceivable by the bare Eye....is most easily perceived through an ordinary Telescope of 18 inches long: Insomuch that we may determine to the greatest Niceity and Exactness, when a Star passes just over the cross-Hairs, even to the single Beat of a Second-Pendulum. And let an Object in the Heavens rise never so little...and the Eye, by means of the Eye-Glass, perceives this Motion, be it never so small." When an Eye is armed with a Telescope. Molyneux follows with some foresightful ruminations, from the first century of the telescope: "And even Natural Philosophy it self may hereby receive the greatest Help, when we consider how Telescopes may be apply'd to many Experiments therein; amongst others, to make the most nice Hygroscope; and has already been used for accurately determining the capricious Variations of the Magnet. Telescopick-Sights have already been successfully apply'd to most exquisite Levels.....every Day will find new Uses for these Sights." (p246) The next topic is the micrometer, beginning with a historical perspective (p246). The first publication to deal with the micrometer was a 'rough Draught' of 12 March, 1667, by Monsieur Petit, Surveyor of the Fortifications in France, as noted in Journal des Scavans of 16 May 1667. Adrien Auzout published in the 28 June 1667 Journal des Scavans his measurements of the diameters of planets, crediting the invention to Picard and Auzout. However, William Gascoigne was the true inventor of the micrometer. The micrometer as an instrument is discussed, with its capabilities, calibration, and use. Molyneux concludes his chapter by describing a glass reticle, to be used instead of cross hairs: "I have often used a curious piece of clear, thin, flat Glass, whereon there are drawn two very fine cross-Lines by the curious Point of a Diamond, smaller than the most fine Wyre or Hair; not easily disturbed by a sleight Touch...nor alterable by Heat and Cold." (p250) Chapter 6, page 251, concerns the history of Optick-Glasses. Optical glasses were not known to the ancients, despite some credulous reports. Roger Bacon in the 13th century probably knew how to combine lenses to make a telescope. On page 262, part of a section on planets, is another of those immortal phrases that make this early literature so rewarding: "...intelligent beings...perhaps are the Inhabitants of these distant Worlds, and of those again infinitely extended beyond these....But in this stupendous Enquiry I stop, as not being able to reach it with the longest Telescope." He continues philosophizing on page 279: "And now I hope it will not be asked, Cui Bono? (for whose benefit, of what good) To what End are all these Discoveries? What Advantage is there in them? For, if the Advancement of Astronomy have any good in it; if the furnishing us with a Contemplation....of admiring the vast Extent, Order and Beauty of the Creation; I am sure, hereby we reap all these Goods in an ample manner. But supposing that nothing of all these Advantages were at hand just at present, let not the inquisitive Philosopher therefore despond in his Enquiries.....But this I say, not so much to encourage men in the Prosecution of useless Enquiries...But to discourage some men from exclaiming against all Labours as absolutely useless, whose immediate Use they do not apprehend." Molyneux concludes his discussion on telescopes with 'two remaining uses of the telescope'. First is a note about a modified telescope used to view nearby objects, such as miniature paintings, which is useful to discover 'the least errors'. This instrument was built in 1685 by Richard Whitehead of London, and described in a paper to the Dublin Society and in a manuscript found in the British Museum titled 'A Way of Viewing Pictures in Miniature'. The second 'remaining use' was to measure the distance of an object from one station, then thought to be impossible. Molyneux proposes using a needle's point mounted on a slide and placed at the focus of the objective. Noting the placement when focused at infinity, one focuses on the object in question and measures how far the needle point needs to be moved to be placed back again at the focal point. By moving the eye side to side in front of the eyepiece, the needle will be seen to move against the background of the object, until the needle is at the focal point, when it will not move. One then estimates the distance to the object by noting the change in focus from infinity. Molyneux notes the limited accuracy of the method. Dioptrica received a few favorable reviews, from Leibniz among others, but no mention was made in Philosophical Transactions, which at that time was infrequently published. Extracts from the book were published in the journal 'Acta Eruditorum' from Leipzig. Christiaan Huygens was given a copy of 'Dioptrica' in 1692, and wrote that the text on telescope optics was superior to previous works. This despite the fact that Molyneux had used both Leibniz's idea that light takes the shortest path, and the corpuscular theory of light, which Huygens had effectively countered in his 'Traite de la lumiere'. Flamsteed had advised Molyneux to delay publication until he was familiar with Huygen's explanation of the wave theory of light. Huygens further noted that the discussion on micrometers in Dioptrica did not mention his text on the subject in Systema Saturnium. However, Huygens was generally complimentary to the book. Molyneux began translating Dioptrica into Latin while the book was being printed in 1692, but this translation is not known to have survived. His personal copy of the book is in the British Library, and includes manuscript addenda, but no corrections, and a listing of the contents that were original to the work: "of 59 propositions, whereof the first part consists, there are as good as 35 wholly new, and amongst the rest many new remarks and operations, and amongst those that are the most common their demonstrations, which in the original authors are very intricate and obscure, are here laid down in a clear and easy method. Also in the second part of seven chapters there are four wholly new and many new things and large remarks in the rest". (Simms p71). A Latin version was published in Amsterdam not long after this. In 1708, the collected correspondence of John Locke was published, and since Molyneux was prominent in this book, renewed attention to him resulted in the reprinting of Dioptrica in 1709, with a new title page, but designated the second edition. Another telescopic title by William Molyneux is: 'Sciothericum telescopicum, or, A new contrivance of adapting a telescope to an horizontal dial for observing the moment of time by day or night: useful in all astronomical observations, and for regulating and adjusting curious pendulum-watches and other time-keepers, with proper tables requisite thereto.' This was published in Dublin, in 1686, and also appeared in the November 1687 'Acta Eruditorum', from Leipzig. It consists of 54 pages of text, followed by 37 pages of tables of the sun's ascension and sundial calculations. Sciothericum comes from the Greek word for sundial. In an attempt to increase the accuracy of astronomical measurements, Molyneux commissioned the eminent instrument maker Richard Whitehead of London to construct a Molyneux designed sundial in 1685. A standard sundial casts a shadow onto a graduated scale; but since the sun subtends one half a degree, the edge of the shadow is blurred over about one half degree of arc, and the exact border of the shadow cannot be observed, limiting the accuracy of the timekeeping. One half degree equals two minutes of time, the approximate limit of accuracy of a standard sundial of any size. A telescope can project an image of the sun with sharp edges and allow increased accuracy. Molyneux's dial had two telescopes, one for the morning and one for the afternoon. The user aligns the telescope tube with the sun, and when an image of the sun is projected behind the telescope, a scale will read the time. The dial was 18 inches in diameter, and presumably the scale could be graduated with 20 or 30 lines between the hours. The device can also be used at night, as a stardial, but the right ascension of the star must be known. Figure 8 of the engraving from Sciothericum shows a tool for finding the meridian (the north-south line), it is used by choosing a particular altitude of the sun, sighting the directions the sun is in when it reaches that altitude in the morning and in the afternoon, and deducing the azimuth of the sun that is half way in between the two directions, this will be the meridian. An appendix to Sciothericum was the first English language printing of the Equation of Time figures derived by Flamsteed, which were much more accurate than earlier tables. Molyneux claimed to be able to "take the time of day or night thereby to five seconds" (Simms p55); and to the Dublin Philosophical Society he lectured that he had "improved the art of dialling, before lame and imperfect, to that accurateness that he can determine the time of day to two seconds, and by a most ingenious application of telescopic sights to it has made it so universal that by any known star he can determine most exactly the time also of the night." (Simms p55) Molyneux's invention was never widely distributed. Philosophical Transactions, Acta Eruditorum - Leipzig, and the Bibliotheque universelle of Le Clerc published notices. Trinity College Cambridge Observatory purchased a dial in 1703. Flamsteed inspected a sundial but thought it should be tested on a very widely separated pair of stars, which test was not entirely successful. However, Molyneux is best known for writings which are far from telescopic. The 'Molyneux Problem' is to this day debated by philosophers & persons who have nothing else to do with their time. The problem in question is, if a man is born blind and learns to distinguish a sphere and a cube using his sense of touch; and then is granted sight, could he recognize the two shapes using vision? If you are an empiricist, like Molyneux & Locke, you believe that all knowledge comes from experience of the world, and claim that the cured blind man could not distinguish the pair without touching them. If you are a rationalist, you believe we are born with abilities including this one. The question was proposed in correspondence with John Locke, who included it in his publications. The debate continues. The most successful & consequential of Molyneux's writings was his book, 'The Case of Ireland’s Being Bound by Acts of Parliament in England, Stated', published in Dublin in 1698, 1706, 1719, 1720, 1725, 1749, 1770, 1773, 1776, and 1782. Molyneux's background to this issue is complicated. He was in the fourth generation of his family to dwell in Ireland, but was not assimilated into Irish society. He was Protestant and part of the ruling class of English origin. For a short time in 1693, he was commissioner of forfeited estates in Ireland. He even dedicated 'The Case of Ireland' to England's King William III. However, English legislation concerning Irish industry had a destructive effect of long standing, and in 1697 the 'woollen laws' brought these issues to a crisis. The book also has a gestation in the rise of Enlightenment thought, the contemporary philosophy that emphasized human reason, and Molyneux's friend John Locke was a leader of this movement. Passages in the book are lifted from Locke's writings; and in turn passages from 'The Case of Ireland' resemble the text of some of the founding documents of the United States. It was a very influential book, although it did not achieve its stated purpose, which was representation for the Irish in the English Parliament that governed Ireland. It did manage to make some people very angry, including the dedicatee, King William, and was condemned by him and the British House of Commons. A widespread rumor that it was burned by the hangman was not accurate. However, public discussion was very heated, with many in Ireland on both sides of the issue, and Molyneux vacated his home for a five week visit with John Locke. In a letter to Locke, Molyneux said, "I think I have treated it with that caution and submission that it cannot justly give any offence, insomuch that I....have presumed to dedicate it to his Majesty." (Hoppen p185) Although there is no doubt Molyneux believed passionately in the ideas he expressed, we are left with an impression of a philosopher-scientist who really thinks that the most inflammatory ideas, if expressed dispassionately and reasonably, will elicit only a reasoned response from the public. The response was in fact rather heated; and in the midst of the furor, Molyneux fell ill and died at age 42. The political Enlightenment espoused in the book was partly a quest for freedom and justice, but also very much a search for a rational system, the same motivation that prompted Molyneux's study of astronomy and thus his instrumental pursuits. The supreme being of the rationalists is to be known in the logic and mathematics of the universe, which could be discovered and comprehended to prove the existence of this deity. And by understanding the rational system of the universe, we can establish a rational system here on earth. Samuel Molyneux, the son of William, was born 1689 in England, died during 1728 in England, and made many important contributions to astronomy and optics. He was the only child to survive infancy, his mother died in 1691 and his father in 1698, thus from 9 years old he was raised by his uncle, Thomas Molyneux. He married the daughter of the Earl of Essex, Elizabeth Diana Capel. Samuel received a B.A. and M.A. from Trinity College, Dublin, was Secretary to the Prince of Wales (later George II), served on the Privy Council and as Lord Commissioner of the Admiralty, and was a member of both the English and the Irish Parliaments. Samuel Molyneux died at 38 years, without offspring, and at auction were sold about 200 lots of instruments, each lot having three or more instruments. Many were originally purchased by William, including a quadrant, microscopes, a helioscope, telescopes, a theodolite, and an instrument for viewing pictures in miniature. Thomas Molyneux survived his nephew and inherited the remainder, until his death in 1733. Robert Hooke claimed to have used a fixed vertical telescope to measure the parallax of Gamma Draconis (which passes through zenith over London), observing a change in position due to the orbit of the earth and allowing a calculation of the distance to the star. Samuel, with James Bradley, attempted to confirm this measurement in 1725. They purchased a George Graham zenith sector, strongly built of soldered tin plate, with a radius of twenty four feet, an arc of 25 arcminutes, and a vernier scale that showed arcseconds. It was mounted in November, 1725 at Samuel's home on Kew Green, by boring holes through the ceiling and roof. A zenith sector swivels at the objective end, and an iron frame was attached to the chimney to mount the objective and suspend the tube. The eyepiece was 3 1/2 feet above the floor. The position of Gamma Draconis was observed over four nights between December 3 and 12, without any measurable change in position. Bradley continued the experiment on 17 December and measured a displacement in declination to the south, in a direction opposite from any possible parallax. He continued observing for a year, and discovered an apparent circular movement in the sky, decreasing in altitude until May, increasing in altitude until September, over a diameter of 39 arcseconds. This unexpected & mysterious observation caused Bradley to do what astronomers have always done when mystified; namely to order a better telescope. George Graham built a superior zenith sector, with a larger range of motion, which Molyneux and Bradley mounted at Wanstead in August 1727. Bradley observed until the end of 1727, at which time he had made sufficient observations to deduce the discovery of nutation and the aberration of light. The famous story of his discovery is that his mysterious measurements suddenly made sense as he was sailing on the Thames and watched a flag in the wind. They deduced from their measurements that light from the sun reached the earth in 8 minutes and 12 seconds, deriving the velocity of light at 318,000 kilometres per second, close to the actual 300,000 km/sec. (Hoppen p198) Molyneux and Bradley also worked to improve the design and fabrication of reflecting telescopes and their efforts were important in the increasing adoption of reflectors to general use. John Hadley devised the methods that achieved the first precision parabolic mirror, but he did not write on the topic. Instead he taught Bradley and Molyneux, who experimented circa 1723 to 1725, finishing their first successful mirror in May 1724, of 26 inches focus, and then another quality speculum of 8 foot focus. Molyneux instructed London opticians Edward Scarlett (the King's Optician) and George Hearne in the techniques and contracted with them to construct telescopes using Hadley's parabolizing methods. Hearne supplied speculum blanks to Molyneux for telescope mirrors, who had limited success as a mirror maker but who conducted many useful experiments, for example trying about 150 different alloys of speculum metal, using copper, brass, tin, and in only one case, arsenic. The most complete English language book on optics during the 1700s was Robert Smith's 'A Compleat System of Opticks' (Cambridge, 1738). This 750 page book included much material on telescopes, including three chapters written or edited by Samuel Molyneux, who had given his papers to Smith and invited Smith to stay in his home and complete the studies. Chapter one of book three in the 'Compleat System' is 'The Method of Grinding and Polishing Glasses for Telescopes, Extracted from Mr. Huygens and Other Authors.' Christiaan Huygens had visited the Royal Society in 1661, informing them of his techniques. Huygens had hosted William Molyneux in 1685, and had given William his studies and experimental results before his death in 1695. In twenty pages of the 'Compleat System', Samuel explained the lens production methods of Huygens. His papers, written in Dutch, had previously been translated into Latin, which Molyneux in turn translated into English, supplemented, and explained. Huygens used metal grinding tools that were three times the diameter of the lens blank. He preferred spherical equiconvex lenses because they were simpler, and was aware of spherical aberration but avoided it by making extremely long focal length optics. He wrote of making lenses 8 3/4 inches in diameter, with a focal length of 200 feet. He mentions the methods described by Cherubin d'Orleans in 'La Dioptrique oculaire' and those of Edward Scarlett. Huygens found that broken looking-glasses were a good source of glass, and tested for striae with a small light in a dark room. The text continues with preparation of tools and glass, grinding, and most extensively with polishing, over eight pages covering various methods and materials for polishing parabolic mirrors. Huygens' polishing machine, and improvements to it by Molyneux, are described in detail. "The Method of Casting, Grinding and Polishing Metals for Reflecting Telescopes, Begun by the Honourable Samuel Molyneux Esquire, and Continued by John Hadley Esquire, Vice-President of the Royal Society," is the chapter found on pages 301-312 of Smith. There is the obligatory English encomium to Isaac Newton, "The greatest improvement which [the telescope] has ever received, is indisputably and singly owing to Sir Isaac Newton, to whose extraordinary sagacity and judicious experiments the world owes...." Molyneux then credits Hadley with the most significant post-Newton improvement in reflectors. The incomplete instructions provided by Hadley (in Philosophical Transactions #376 of April 1723) were used by Molyneux and James Bradley to produce several telescopes, with the idea of formulating the procedure into a process that could be followed by any skilled craftsman, 'without the assistance of a fortune which could well bear the disappointment'. The first person to follow the instructions was Mr. Hauksbee of Crane Court, who made 3 1/2 foot, 6 foot, and 12 foot reflectors. Molyneux & Bradley then contacted professional instrument makers Edward Scarlett & George Hearne and taught them the procedure, to encourage the production of inexpensive & widely used telescopes; however these never became as cheap or as common as hoped. This motivated Molyneux and Hadley to write the 11 pages of instructions for mirror making included in Robert Smith's 'Optics', from casting the metal, through grinding and polishing the mirror. Molyneux continues his contribution to 'A Compleat System of Opticks' with the chapter, "Sir Isaac Newton's Reflecting Telescope Made and Described by the Honourable Samuel Molyneux Esquire, and Presented by Him to His Majesty John V. King of Portugal: with Other Kinds of Mechanisms for This and for Mr. Gregory's Reflecting Telescope." This is Molyneux's account of his Newtonian reflector made for the King of Portugal at an unspecified date. He describes a few details of the mirror cell, without noting them to be ideas original to himself. It does not seem to be an adjusting cell. The polished face of the mirror is placed against three stops of wood. The closed back end of the tube is bored to accept three screws designed to hold the mirror against the stops. These screws must be "gently and tenderly skrewed, only just sufficient to bear the metal against the stops", lest the figure be distorted. The engraving shows a mirror placed against the back of the tube, and through the back pass three thumbscrews. Most of this five page essay is an instruction manual written for a rank beginner at telescope operation; for example the Newtonian is described: "This sort of telescope in respect of a common glass, one being to be used in the same manner as a German Flute is in respect of a common one." Seeing conditions are described, focusing is explained in detail, as is the use of the finder scope. An illustration of the particular instrument is followed by a plate showing Hadley's design for a mount, with horizontal and vertical motion. Hadley is also credited with a mount for a Gregorian, where a ball & socket is secured to a vertical post. This telescope was a prototype for Molyneux's planned standardized telescope that could be built by unspecialized craftsman. Samuel fabricated it with a 2 foot focus and silver trim. It was presented by the Prince of Wales to King John V of Portugal, who in turn gave it to Francesco Bianchini of Bologna Observatory in Italy, who bequeathed it Cardinal Davia, who donated it to the Institute of Science in Bologna. The telescope is in an inventory of the Institute from 1843, after which it was lost. Molyneux's contribution to Smith's book is by far the most extensive English language telescope making manual of its time, and was an important contribution to the art. ============================================= Bibliography. Bayne, Ronald. Molyneux, William. Dictionary of National Biography. London: Smith, Elder & Co., 1909. Clerke, Agnes M. Molyneux, Samuel. Dictionary of National Biography. London: Smith, Elder & Co., 1909. Hoppen, K. Theodore. The Common Scientist in the Seventeenth Century; a study of the Dublin Philosophical Society 1683-1708. Charlottesville: University Press of Virginia, 1970. Kargon, Robert. Molyneux, William. Dictionary of Scientific Biography. Charles Gillispie, ed. New York: Scribner, 1970-. Molyneux, William. Dioptrica nova, A treatise of dioptricks in two parts, wherein the various effects and appearances of spherick glasses, both convex and concave, single and combined, in telescopes and microscopes, together with their usefulness in many concerns of humane life, are explained. London: Benj. Tooke, 1692. 301pp. Molineux, William. A Dioptrick Problem, Why four Convex-glasses in a Telescope, shew Objects Erect. Philosophical Transactions of the Royal Society 16 (1686-1692) 169-172 (#183). Molyneux, William. Sciothericum telescopicum, or, A new contrivance of adapting a telescope to an horizontal dial for observing the moment of time by day or night: useful in all astronomical observations, and for regulating and adjusting curious pendulum-watches and other time-keepers, with proper tables requisite thereto. Dublin: Andrew Crook and Samuel Helsham, 1686. 54 + 37pp. Molyneux, William. Partial translation of Gottfried Leibniz, 'Unicum opticae catoptricae et dioptricae principium'. Acta eruditorum, June 1682, pp185-190. Plotkin, Howard. Molyneux, Samuel. Dictionary of Scientific Biography. Charles Gillispie, ed. New York: Scribner, 1970-. Simms, John Gerald. William Molyneux of Dublin, 1656-1698. (edited by P.H. Kelly) Blackrock, County Dublin: Irish Academic Press, c1982. Smith, Robert. A Compleat System of Opticks in Four Books, viz. A popular, a mathematical, a mechanical, and a philosophical treatise. To which are added remarks upon the whole. Cambridge, 1738. Vol.1, 280pp; Vol.2, pp281-455. ---------------------- Further References: http://dns.bo.astro.it/dip/Museum/english/index_2.html Bologna Observatory, Samuel Molyneux's telescope for the King of Portugal Ball, R.S. Great Astronomers. Cambridge, 1895. Bradley, James. A Description of an Instrurnent Set up at Kew, in Surrey, for Investigating the Annual Parallax of the Fixed Stars, with an Account of the Observations Made Therewith. S. P. Rigaud, ed. Miscellaneous Works and Correspondence of the Rev. James Bradley. Oxford, 1832. pp93-115. Bradley, James. Observations Made at Kew. S. P. Rigaud, ed. Miscellaneous Works and Correspondence of the Rev. James Bradley. Oxford, 1832. pp116-193, observations by Bradley after 22 April 1726. Hoppen, K.T. The Royal Society and Ireland: William Molyneux, F.R.S. (1656-1698). Notes and Records of the Royal Society, 18 (1963), 125-35. King, Henry C. The History of the Telescope. New York: Dover Publications, 1979 (1955). 456pp. Maunder, E. Walter. The Royal Observatory Greenwich; a glance at its history and work. 1900. Willmoth, Frances, ed. Flamsteed's Stars: New perspectives on the life and work of the first Astronomer Royal (1646-1719). Woodbridge, Suffolk: Boydell Press, 1997. pp107-114, Hester Higton, Equipping an Observatory: Flamsteed and Molyneux Discuss an Astronomical Quadrant. ====================================================== 15 September, 2002 home page: http://home.europa.com/~telscope/binotele.htm