|Authorised form of name||Huygens; Christian (1629 - 1695); natural philosopher|
|Other forms of name||Huyghens, Christiaan|
|Dates||1629 - 1695|
|Dates and places||Birth: |
The Hague, Netherlands (14 April 1629)
The Hague, Netherlands (08 June or 08 July 1695)
|Activity||Research Field: |
Physics, mathematics, astronomy, optics
Taught by his father; law and mathematics at University of Leyden (1645-1647); law at Collegium Arausiacum (College of Orange) at Breda (1647-1649); LLD (1655, Angers)
Discovered the satellite of Saturn and recognized its ring (1655-6); invented the pendulum clock (1656);
Travelled to Denmark with Henry, Count of Nassau (1649); travelled to France (1655, 1660) and England (1661, 1663); lived in Paris (1666-1681)
Academie Royale des Sciences (1665: First foreigner to become a Member)
Christiaan Huygens came from an important Dutch family. His father Constantin Huygens had studied natural philosophy and was a diplomat. It was through him that Christiaan was to gain access to the top scientific circles of the times. In particular Constantin had many contacts in England and corresponded regularly with Mersenne and was a friend of Descartes.
Tutored at home by private teachers until he was 16 years old, Christiaan learned geometry, how to make mechanical models and social skills such as playing the lute. His mathematical education was clearly influenced by Descartes who was an occasional visitor at the Huygens' home and took a great interest in the mathematical progress of the young Christiaan.
Christiaan Huygens studied law and mathematics at the University of Leiden from 1645 until 1647. Van Schooten tutored him in mathematics while he was in Leiden. From 1647 until 1649 he continued to study law and mathematics but now at the College of Orange at Breda. Here he was fortunate to have another skilled teacher of mathematics, John Pell. Through his father's contact with Mersenne, a correspondence between Huygens and Mersenne began around this time. Mersenne challenged Huygens to solve a number of problems including the shape of the rope supported from its ends. Although he failed at this problem he did solve the related problem of how to hang weights on the rope so that it hung in a parabolic shape.
In 1649 Huygens went to Denmark as part of a diplomatic team and hoped to continue to Stockholm to visit Descartes but the weather did not allow him to make this journey. He followed the visit to Denmark with others around Europe including Rome.
Huygens's first publications in 1651 and 1654 considered mathematical problems. The 1651 publication Cyclometriae showed the fallacy in methods proposed by Gregory of Saint-Vincent, who had claimed to have squared the circle. Huygens' 1654 work De Circuli Magnitudine Inventa was a more major work on similar topics.
Huygens soon turned his attention to lens grinding and telescope construction. Around 1654 he devised a new and better way of grinding and polishing lenses. Using one of his own lenses, Huygens detected, in 1655, the first moon of Saturn. In this same year he made his first visit to Paris. He informed the mathematicians in Paris including Boulliau of his discovery and in turn Huygens learnt of the work on probability carried out in a correspondence between Pascal and Fermat. On his return to Holland Huygens wrote a small work De Ratiociniis in Ludo Aleae on the calculus of probabilities, the first printed work on the subject.
The following year he discovered the true shape of the rings of Saturn. However others had different theories including Roberval and Boulliau. Boulliau had failed to detect Saturn's moon Titan so Huygens realised that he was using an inferior telescope. By 1656 Huygens was able to confirm his ring theory to Boulliau and the results were reported to the Paris group. In Systema Saturnium (1659), Huygens explained the phases and changes in the shape of the ring. Some, including the Jesuit Fabri, attacked not only Huygens theories but also his observations. However by 1665 even Fabri was persuaded to accept Huygens' ring theory as improving telescopes confirmed his observations.
Work in astronomy required accurate timekeeping and this prompted Huygens to tackle this problem. In 1656 he patented the first pendulum clock, which greatly increased the accuracy of time measurement. His work on the pendulum was related to other mathematical work which he had been doing on the cycloid as a result of the challenge by Pascal. Huygens believed that a pendulum swinging in a large are would be more useful at sea and he invented the cycloidal pendulum with this in mind. He built several pendulum clocks to determine longitude at sea and they underwent sea trials in 1662 and again in 1686. In the Horologium Oscillatorium sive de motu pendulorum (1673) he described the theory of pendulum motion. He also derived the law of centrifugal force for uniform circular motion. As a result of this Huygens, Hooke, Halley and Wren formulated the inverse-square law of gravitational attraction.
Huygens returned to Paris in 1660 and went to meetings of various scientific societies there. He wrote, in a letter to his brother:-
... there is a meeting every Tuesday [at Montmor's house] where twenty or thirty illustrious men are found together. I never fail to go ... I have also been occasionally to the house of M Rohault, who expounds the philosophy of M Descartes and does very fine experiments with good reasoning on them.
At these societies he met many mathematicians including Roberval, Carcavi, Pascal, Pierre Petit, Desargues and Sorbière. After Pascal visited him in December 1660 Huygens wrote
... we talked of the force of water rarefied in cannons and of flying, I showed him my telescopes...
In 1661 Huygens visited London, particularly to find out more about the newly forming Royal Society meeting at that time in Gresham College. He was greatly impressed with Wallis and the other English scientists whom he met and, from this time on, he was to continue his contacts with this group. He showed his telescopes to the English scientists and they proved superior to those in use in England. The Duke and Duchess of York came to observe the Moon and Saturn through Huygens' telescope. While in London Huygens saw Boyle's vacuum pump and he was impressed. After his return to the Hague he carried out a number of Boyle's experiments for himself. Huygens was elected to the Royal Society of London in 1663.
At this time Huygens patented his design of pendulum clock with the solution of the longitude problem in mind. In 1665 he learnt that the Royal Society was investigating other forms of clock, in particular Hooke was experimenting with a spring regulated clock. Huygens wrote to Hooke doubting this approach which he felt would be unduly affected by temperature changes. Despite this Huygens did begin to experiment with clocks regulated by springs, but their accuracy was poorer than his pendulum clocks.
Huygens accepted an invitation from Colbert in 1666 to become part of the Académie Royale des Sciences. He arrived in Paris that year to discover that the Society was not yet organised. After meetings were held with Roberval, Carcavi, Auzout, Frenicle de Bessy, Auzout and Buot in Colbert's library the Society moved to the Bibliothèque du Roi where Huygens took up residence. He assumed leadership of the group basing much on his knowledge of the way the Royal Society operated in England.
Huygens' work on the collision of elastic bodies showed the error Descartes' laws of impact and his memoir on the topic was sent to the Royal Society in 1668. The Royal Society had posed a question on impact and Huygens proved by experiment that the momentum in a fixed direction before the collision of two bodies is equal to the momentum in that direction after the collision. Wallis and Wren also answered this question.
Circular motion was a topic which Huygens took up at this time but he also continued to think about Descartes' theory of gravity based on vortices. He seems to have shown signs of being unhappy with Descartes' theory around this time but he still addressed the Académie on this topic in 1669 although after his address Roberval and Mariotte argued strongly, and correctly, against Descartes' theory and this may have influenced Huygens.
From his youth Huygens' health had never been robust and in 1670 he had a serious illness which resulted in him leaving Paris for Holland. Before he left Paris, believing himself to be close to death he asked that his unpublished papers on mechanics be sent to the Royal Society. The secretary to the English ambassador was called and described Huygens' reasons:-
... he fell into a discourse concerning the Royal Society in England which he said was an assembly of the choicest wits in Christendom ... he said he chose to deposit those little labours ... in their hands sooner than any else. ... he said he did foresee the dissolution of this Academy because it was mixed with tinctures of envy because it was supported upon suppositions of profit because it wholly depended upon the humour of a prince and the favour of a minister...
By 1671 Huygens returned to Paris. However in 1672 Louis XIV invaded the Low Countries and Huygens found himself in the extremely difficult position of being in an important position in Paris at a time France was at war with his own country. Scientists of this era felt themselves above political wars and Huygens was able, with much support from his friends, to continue his work.
In 1672 Huygens and Leibniz met in Paris and thereafter Leibniz was a frequent visitor to the Académie. In fact Leibniz owes much to Huygens from whom he learnt much of his mathematics. In this same year Huygens learnt of Newton's work on the telescope and on light. He, quite wrongly, criticised Newton's theory of light, in particular his theory of colour. His own work, Horologium Oscillatorium sive de motu pendulorum appeared in 1673 and showed that Huygens had moved far from Descartes' influence.
Horologium Oscillatorium contains work on the pendulum. In it Huygens proves that the cycloid is tautochronous, an important theoretical result but one which had little practical application to the pendulum. He also solves the problem of the compound pendulum. However there is much more than work on pendulums. Huygens describes the descent of bodies in a vacuum, either vertically or along curves. He defines evolutes and involutes of curves and, after giving some elementary properties, finds the evolutes of the cycloid and of the parabola. Huygens attempts for the first time in this work to study the dynamics of bodies rather than particles.
Papin worked as an assistant to Huygens around this time and after he left to work with Boyle, Huygens was joined by Tschirnhaus. Another bout of illness in 1676 saw Huygens return to the Hague again. He spent two years there, in particular studying the double refraction Bartholin had discovered in Iceland spar crystal. He also worked on the velocity of light which he believed was finite and was pleased to hear of Römer's experiments which gave an approximate velocity for light determined by observing Jupiter's moons.
By 1678 Huygens had returned to Paris. In that year his Traité de la lumiere appeared, in it Huygens argued in favour of a wave theory of light. Huygens stated that an expanding sphere of light behaves as if each point on the wave front were a new source of radiation of the same frequency and phase. However his health became even more unreliable and he became ill in 1679 and then again in 1681 when he returned to the Hague for the last time. La Hire, who had always argued against foreigners in the Académie, sent his best wishes to Huygens but he clearly hoped that he would not return so that he might himself might acquire his position.
The longitude problem had remained a constant cause for Huygens to continue work on clocks all his life. Again after his health returned he worked on a new marine clock during 1682 and, with the Dutch East India Company showing interest, he worked hard on the clocks. Colbert died in 1683 and a return to Paris without the support of his patron seemed impossible. His father died in 1687, having reached 91 years of age, and the following year his brother left for England. Huygens missed having people around him with whom he could discuss scientific topics. In 1689 he came to England.
In England Huygens met Newton, Boyle and others in the Royal Society. It is not known what discussions went on between Huygens and Newton but we do know that Huygens had a great admiration for Newton but at the same time did not believe the theory of universal gravitation which he said
appears to me absurd.
In some sense of course Huygens was right, how can one believe that two distant masses attract one another when there is nothing between them, nothing in Newton's theory explains how one mass can possible even know the other mass is there. Writing about Newton and the Principia some time later Huygens wrote:-
I esteem his understanding and subtlety highly, but I consider that they have been put to ill use in the greater part of this work, where the author studies things of little use or when he builds on the improbable principle of attraction.
He departed with much sadness at the thoughts of his scientific isolation in Holland.
In the final years of his life Huygens composed one of the earliest discussions of extraterrestrial life, published after his death as the Cosmotheoros (1698). He continued to work on improving lenses and on a spring regulated clock and on new pendulum clocks.
Huygens described the 31-tone equal temperament in Lettre touchant le cycle harmonique. This has led indirectly to a tradition of 31-tone music in the Netherlands in this century.
In a letter to Tschirnhaus written in 1687, Huygens explained his own approach:-
.. great difficulties are felt at first and these cannot be overcome except by starting from experiments ... and then be conceiving certain hypotheses ... But even so, very much hard work remains to be done and one needs not only great perspicacity but often a degree of good fortune.
Huygens scientific achievements are summed up in  as follows:-
... Huygens was the greatest mechanist of the seventeenth century. He combined Galileo's mathematical treatment of phenomena with Descartes' vision of the ultimate design of nature. Beginning as an ardent Cartesian who sought to correct the more glaring errors of the system, he ended up as one of its sharpest critics. ... the ideas of mass, weight, momentum, force, and work were finally clarified in Huygens' treatment of the phenomena of impact, centripetal force and the first dynamical system ever studied - the compound pendulum.
Article by: J J O'Connor and E F Robertson
|Royal Society activity||Membership: |
|Relationships||Son of Constantin Huygens, Secretary and Counsellor to the Princes of Orange and his wife, Susanne Van Baerle|
|Published works||Theoremata de quadratura hyperboles, ellipsis et circuli (1651), includes refutation of Gregory of St Vincent's quadrature of the circle; De circuli magnitudine inventa (1654); Tractatus de rationciniis in aleae ludo (1657); Horologium oscillatorum (1673); |
Bulloch's Roll; DSB; Biographie Universelle
Name from Hunter; altname from Bulloch's Roll
D T Whiteside, 'The Prehistory of the Principia from 1664 to 1686' in NR 1991 vol 45 pp 11-61
H A M Snelders, 'Christiaan Huygens and Newton's Theory of Gravitation' in NR 1989 vol 43 pp 209-222
J H Leopold, 'Clockmaking in Britain and the Netherlands' in NR 1989 vol 43 pp 155-165
A R Hall, 'The Leeuwenhoek Lecture, 1988. Antoni van Leeuwenhoek 1632-1723' in NR 1989 vol 43 pp 249-273
D S Landes, 'The Wilkins Lecture, 1988. Hand and Mind in Time Measurement: the Contributions of Art and Science' in NR 1989 vol 43 pp 57-69
A R Hall, 'Chairman's Remarks' in NR 1989 vol 43 pp 97-98
A E Shapiro, 'Huygens' Traite de la Lumiere and Newton's Opticks: Pursuing and Eschewing Hypotheses' in NR 1989 vol 43 pp 223-247
E A Fellmann, 'The Principia and Continental Mathematicians' in NR 1988 vol 42 pp 13-34
Laurel Brodsley, Sir Charles Frank and John W Steeds, 'Prince Rupert's Drops' in NR 1986-87 vol 41 pp 1-26
A A Mills and R Hall, 'The Production of a Plane Surface. As Illustrated by Specula From Some Early Newtonian Telescopes' in NR 1982-83 vol 37 pp 147-166
Simon Schaffer, 'Halley's Atheism and the End of the World' in NR 1977-8 vol 32 pp 17-40
Marie Boas Hall, 'The Royal Society's Role in the Diffusion of Information in the Seventeenth Century' in NR 1974-5 vol 29 pp 173-192
Albert Van Helden, 'Christopher Wren's De Corpore Saturni' in NR 1968 vol 23 pp 213-229
E Faure-Fremiet, 'Les Origines de l'Academie des Sciences de Paris' in NR 1966 vol 21 pp 20-31
J E McGuire and P M Rattansi, 'Newton and the "Pipes of Pan"' in NR 1966 vol 21 pp 108-143
J A Lohne, 'Isaac Newton: the Rise of a Scientist 1661-1671' in NR 1965 vol 20 pp 125-139
E N da C Andrade, 'The Birth and Early Days of the Philosophical Transactions' in NR 1965 vol 20 pp 9-27
R K Bluhm, 'Henry Oldenburg, FRS (c 1615-1677)' in NR 1960 vol 15 pp 183-197
Angus Armitage, 'William Ball, FRS (1627-1690)' in NR 1960 vol 15 pp 167-172
H W Robinson, 'Gleanings from the Library - I. A Note on the Early Minutes' in NR 1938 vol 1 pp 92-95
S Mandelbrote, 'From Bremen to Pall Mall. Henry Oldenburg. Shaping The Royal Society, by M B Hall' in NR 2002 vol 56 pp 389-390
J S Rowlinson, 'Gases and liquids. How fluids unmix: discoveries by the school of Van der Waals and Kamerlingh Onnes, by J L Sengers' in NR 2003 vol 57 pp 255-256
H Gest, 'The Discovery of Microorganisms by Robert Hooke and Antoni von Leeuwenhoek, Fellows of the Royal Society' in NR 2004 vol 58 pp 187-201
S Van Damme, 'The Dutch Galileo? The Greatness of Huygens' Science. 'Huygens The man begind the principle' by C D Andriesse translated by Sally Miedema', in NR 2006 vol 60 pp 219-220
Various possible death dates: DSB gives 08 Jul 1695, index to BR gives 08 June 1695, BR gives 08 Jul 1693, Hunter gives 1695.
|Royal Society code||NA8062|
|EL/H1/16||Extract of a letter from Christian Huygens to Robert Moray ||1662|
|EL/H1/79||Christian Huygens, dated at Paris, to John Wallis||10 July 1673|
|EL/H1/73||Christian Huygens, dated at Paris, to Henry Oldenburg||1 July 1672|
|EL/H1/72||Christian Huygens, dated at Paris, to Henry Oldenburg||9 April 1672|
|EL/H1/75||Christian Huygens, dated at Paris, to Henry Oldenburg||14 January 1673|
|EL/H1/69||Christian Huygens, dated at the Hague, to Henry Oldenburg||15 October 1670|
|EL/H1/78||Christian Huygens, dated at Paris, to Henry Oldenburg||4 June 1673|
|EL/H1/43||Transcription of a letter from Christian Huygens to Robert Moray||1665|
|EL/H1/64||Christian Huygens, dated at Paris, to Henry Oldenburg||26 June 1669|
|EL/H1/85||Christian Huygens, dated at Paris, to Henry Oldenburg||11 July 1675|
|EL/M1/25||Robert Moray, dated at Whitehall, to Christian Huygens||15 February 1669|
|EL/H1/45||Christian Huygens, dated at the Hague, to Robert Moray ||6 February 1665|
|EL/H1/47||Christian Huygens, dated at the Hague, to Robert Moray ||6 March 1665|
|EL/H1/51||Partial transcription of a letter from Christian Huygens to Robert Moray ||1665|
|EL/H1/76||Christian Huygens, dated at Paris, to Henry Oldenburg||10 February 1673|
|EL/H1/29||Letter from Christian Huygens, dated at Paris||1664|
|EL/H1/54||Transcription of a letter from Christian Huygens to Robert Moray ||1665|
|EL/H1/57||Christian Huygens, dated at Paris, to Henry Oldenburg||13 November 1668|
|EL/H1/21||Copy of a letter from Christian Huygens||2 September 1663|
|EL/H1/12||Christian Huygens to Robert Moray||nd|
|EL/H1/17||Christian Huygens, dated at the Hague, to Robert Moray ||20 December 1662|
|EL/H1/53||Christian Huygens, dated at the Hague, to Robert Moray ||24 December 1665|
|EL/H1/7||Christian Huygens, dated at the Hague, to Robert Moray||4 January 1662|
|EL/H1/22||Christian Huygens, dated at Paris, to Robert Moray ||11 November 1663|
|EL/H1/31||Christian Huygens, dated at the Hague, to Robert Moray ||27 June 1664|
|EL/H1/14||Christian Huygens, dated at the Hague, to Robert Moray||18 August 1662|
|EL/H1/26||Christian Huygens, dated at Paris, to Robert Moray ||January 1664|
|EL/H1/41||Transcription of a letter from Christian Huygens to Robert Moray ||1664|
|EL/H1/28||Christian Huygens, dated at Paris, to Robert Moray ||12 March 1664|
|EL/H1/88||Christian Huygens, dated at Paris, to Henry Oldenburg||21 November 1675|
|EL/H1/55||Christian Huygens, dated at the Hague, to Robert Moray ||9 April 1666|
|EL/H1/20||Christian Huygens, dated at Paris, to Robert Moray ||1 June 1663|
|EL/H1/15||Christian Huygens, dated at the Hague, to Robert Moray||1 December 1662|
|EL/H1/25||Christian Huygens, dated at Paris, to Robert Moray ||19 December 1663|
|EL/W2/8||John Wallis, dated at London, to Christian Huygens||30 May 1673|
|EL/H1/24||Christian Huygens, dated at Paris, to Robert Moray ||9 December 1663|
|EL/H1/10||Christian Huygens, dated at the Hague, to Robert Moray||24 February 1662|
|EL/H1/1||Christian Huygens, dated at the Hague, to Robert Moray||24 June 1661|
|EL/H1/48||Christian Huygens, dated at the Hague, to Robert Moray ||27 March 1665|
|EL/H1/8||Christian Huygens, dated at the Hague, to Robert Moray||3 February 1662|
|EL/H1/6||Christian Huygens, dated at the Hague, to Robert Moray||30 December 1661|
|EL/H1/3||Christian Huygens, dated at the Hague, to Robert Moray||1 August 1661|
|EL/H1/27||Christian Huygens, dated at Paris, to Robert Moray ||20 February 1664|
|EL/H1/2||Christian Huygens to Robert Moray||15 July 1661|
|EL/H1/4||Christian Huygens, dated at the Hague, to Robert Moray||16 September 1661|
|EL/H1/74||Christian Huygens, dated at Paris, to Henry Oldenburg||27 September 1672|
|EL/H1/50||Christian Huygens, dated at the Hague, to Robert Moray ||29 May 1665|
|EL/O2/120||Henry Oldenburg, dated at London, to Christian Huygens||23 June 1673|
|EL/H1/58||Christian Huygens, dated at Paris, to John Wallis||13 November 1668|
|EL/H3/28||Christian Huygens, dated at Paris, to Constantin Huygens||17 August 1674|
|EL/H1/59||Christian Huygens, dated at Paris, to Robert Moray||30 March 1669|
|MM/11/27||'Report of Warren De La Rue FRS on the proposal to remount the Object Glass of Huyghens'||22 January 1855|
|EL/H1/71||Christian Huygens, dated at Paris, to Henry Oldenburg||13 February 1672|
|EL/H1/35||Christian Huygens, dated at the Hague, to Robert Moray ||29 August 1664|
|EL/H1/65||Christian Huygens, dated at Paris, to Henry Oldenburg||10 August 1669|
|EL/O2/114||Henry Oldenburg, dated at London, to Christian Huygens||2 June 1673|
|EL/H1/62||Christian Huygens, dated at Paris, to Henry Oldenburg||6 February 1669|
|EL/H1/39||Transcription of a letter from Christian Huygens, dated at the Hague, to Robert Moray||1664|
|EL/H1/63||Christian Huygens, dated at Paris, to Henry Oldenburg||29 May 1669|
|EL/H1/60||Christian Huygens, dated at Paris, to Henry Oldenburg||30 March 1669|
|RBO/2i/69||'A Description Of a New kind of Candlestick' by Christian Huygens||2 September 1663|
|RBO/2i/54||An experiment of Christian Huygens 'touching the Suspension of Water in a Bolt-head after the Receiver had been well exhausted' ||8 July 1663|
|RBO/4/23||'Anagrammata Propositionum XIV quae quam primum licebit explicanda' by Christian Huygens||4 September 1669|
|DM/2/125||Sheet of notes regarding the Huygens object-glass||c.19th century|
|CLP/3i/46||Paper, 'Cyphers of Christian Huygens and Christopher Wren'||4 February 1668|
|RBO/4/9||'De Motu Corporum ex mutuo impulsu Hyopothesis' by Christian Huygens||1669|
|RBC/2/27||'A Description of a New kind of Candlestick presented by Monsieur Hugens September 2 1663 in French and Englished by the Secretary'||1663|
|RBO/2ii/57||'A Description of a New kind of Candlestick presented by Monsieur Huygens'||2 September 1663|
|EL/H1/11||Christian Huygens, dated at the Hague, to Robert Moray||14 July 1662|
|RBO/2ii/43||'An Accompt of the ground of a Waterpitt boared at Amsterdam presented to the Society by Mons Huygens'||24 June 1663|
|RBO/4/21||'Animadversiones in novam Theoriam Motus' of Christopher Wren and Christian Huygens||1669|
|RBO/4/14||A Cypher of Mons. Christian Huygens de Zulichem ||4 February 1669|
|RBO/2i/52||'An Account of the Ground of a water-pit boared at Amsterdam' by Christian Huygens||24 June 1663|
|MM/14/47||Letter from J Drummond Robertson,Torquay, to William Douglas||28 February 1930|
|MM/14/50||Letter from J Drummond Robertson., Torquay, to William Douglas||30 March 1930|
|MM/14/52||Letter from Alexander Miller, Edinburgh, to William Douglas||30 April 1930|
|MM/14/53||Letter from JA Vollgraff, Leyden, to the Royal Society||28 September 1947|
|CLP/4i/27||Paper, discussion of Christian Huygens' work on the 'phenomena of Rarefaction' by an anonymous author||[c 17th Century]|
|CLP/3i/56/3||Table, discoveries in anagrams by Christian Huygens||4 September 1669|
|EL/O1/87||Henry Oldenburg, dated at London, to Christian Huygens||16 November 1668|
|LBO/1/7||Copy extract of letter from Christian Huygens, the Hague, to Robert Moray ||24 June 1661|
|CLP/3i/54/4||Equations, criticism of Wren's theory of motion by Francis Willughby||1669|
|NLB/13/419||Copy letter from Theodore E James, to the Netherlands Charge d'Affaires||29 August 1896|
|NLB/13/412||Copy letter from Theodore E James, to Michael Foster||24 August 1896|
|NLB/13/416||Copy letter from Michael Foster, to the Netherlands Charge d'Affaires, 118 Eaton Square, Upper Belgrave Street, S.W. ||26 August 1896|
|NLB/13/420||Copy letter from Theodore E James, to W Crouch, Grafton House, Wanstead||27 August 1896|
|NLB/13/417||Copy letter from Michael Foster, to the Secretary, Huygens Commission, the Hague||26 August 1896|
|NLB/15/485||Copy letter from Robert William Frederick Harrison, to Dr Johannes Bosscha, Haarlem, Holland||13 October 1897|
|CLP/3i/54/1||Paper, 'Animadversiones in novam theoriam [amendments to the new theory] of Christopher Wren and Christian Huygens' by Francis Willughby||1669|
|NLB/62/32||Copy letter from Frederick Alexander Towle, Assistant Secretary of the Royal Society; to Dr. D. V. Korteweg; Amsterdam||21 November 1921|
|NLB/59/290||Copy letter from Edwin Deller, Assistant Secretary of the Royal Society; to Dr. D. V. Korteweg; Amsterdam||30 August 1920|
|CLP/3i/54||Paper, 'Animadversiones in novam theoriam [amendments to the new theory] of Christopher Wren and Christian Huygens' by Francis Willughby||1669|
|CLP/24/8||Paper, 'Concerning the controversy between Monsieur Huygens and James Gregory' by John Collins||17th century|
|CLP/3i/45/7||Diagram, the motion of bodies resulting from impact by Christian Huygens||1668|
|CLP/2/19||Paper, regarding telescopes invented before 1609 by John Eames||1726|
|CLP/7i/31||Paper, concerning the dispute between Huygens and M Renau||[c1700]|
|CLP/1/22||Paper, 'An answer to monsieur Huygens' by James Gregory||1668|
|EL/H1/19||Partial translation of a letter from Christian Huygens to Robert Moray ||1663|
|CLP/1/15/3||Diagrams on the pendulum by William Brouncker||22 January 1662|
|CLP/3i/56/1||Paper, 'Anagrammata' by Christian Huygens||4 September 1669|
|CLP/3i/45/5||Diagram, the motion of bodies resulting from impact by Christian Huygens||1668|
|CLP/1/15/2||Diagrams on the pendulum by William Brouncker||22 January 1662|
|CLP/3i/45/1||Paper, 'De motu corporum ex multuo impulsu' [On the motion of bodies resulting from impact] by Christian Huygens||1668|
|CLP/3i/56/2||Table, discoveries in anagrams by Christian Huygens||4 September 1669|
|CLP/3i/45/2||Diagram, the motion of bodies resulting from impact by Christian Huygens||1668|
|CLP/3i/45/6||Diagram, the motion of bodies resulting from impact by Christian Huygens||1668|
|CLP/1/11/6||Diagram, erroneous diagram for Brouncker's paper on the pendulum by Christopher Wren||1669|
|CLP/1/15/1||Paper, 'Imagine the curve AXC to be made up of an infinite number of equal sides...' by William Brouncker||22 January 1662|
|CLP/1/15||Paper, 'Imagine the curve AXC to be made up of an infinite number of equal sides...' by William Brouncker||22 January 1662|
|CLP/1/13/1||Paper, 'Problema alhasein' [alhasein problem] by Christian Huygens at Paris||26 June 1669|
|CLP/1/13/2||Diagram, Alhazen's problem by Christian Huygens at Paris||26 June 1669|
|CLP/1/13||Paper, 'Problema alhasein' [alhasein problem] by Christian Huygens at Paris||26 June 1669|
|CLP/1/31||Copy letter, from James Gregory with considerations of Christian Huygens' work to the publisher of 'Philosophical Transactions'||1668|
|CLP/4i/23/1||Drawing, modification of an air pump by Christian Huygens||28 January 1663|
|EL/A/13||Partial translation of a letter, from Adrian Auzout to Henry Oldenburg||1666|
|CLP/3i/54/3||Equations, criticism of Wren's theory of motion by Francis Willughby||1669|
|CLP/7i/31/2||Diagram for manoeuvering ships by Robert Hooke||[c1700]|
|CLP/7i/31/1||Paper, concerning the dispute between Huygens and M Renau||[c1700]|
|CLP/8i/51/2||Copy diagram, Saturn by Christian Huygens||[c17th Century]|
|CLP/3i/10||Paper, 'A description of a new kind of candlestick' presented by Christian Huygens||1663|
|MOB/016||Aerial telescope parts by Christiaan Huygens||1691|
|CLP/3i/54/2||Diagram, criticism of Wren's theory of motion by Francis Willughby||1669|
|CLP/3i/45/4||Diagram, the motion of bodies resulting from impact by Christian Huygens||1668|
|EL/H1/5||Christian Huygens, dated at the Hague, to Robert Moray||4 November 1661|
|EL/H1/61||Christian Huygens, dated at Paris, to Henry Oldenburg||5 January 1669|
|EL/H1/70||Christian Huygens, dated at the Hague, to Henry Oldenburg||October 1670|
|RBC/2/13||'An Account of the Ground of a Waterpitt Boared at Amsterdam presented to the Society' by Christian Huygens||24 June 1663|
|EL/H1/32||Christian Huygens, dated at the Hague, to Robert Moray ||18 July 1664|
|EL/H1/82||Christian Huygens, dated at Paris, to Henry Oldenburg||20 February 1675|
|EL/H1/84||Christian Huygens, dated at Paris, to Henry Oldenburg||21 June 1675|
|EL/H1/9||Christian Huygens, dated at the Hague, to Robert Moray||10 February 1662|
|EL/H1/44||Christian Huygens, dated at the Hague, to Robert Moray ||16 January 1665|
|EL/H1/33||Christian Huygens, dated at the Hague, to Robert Moray ||8 August 1664|
|EL/O2/153||Henry Oldenburg, dated at London, to Christian Huygens||11 March 1675|
|EL/H1/66||Christian Huygens, dated at Paris, to Henry Oldenburg||4 September 1669|
|CLP/9i/10||Paper, an account of the ground of a waterpit bored at Amsterdam by Christian Huygens||24 June 1663|
|NLB/13/434||Copy letter from Theodore E James, to Professor Michael Foster||7 September 1896|
|NLB/60/828||Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to S. B. Gaythorpe Esquire; 3 Prospect Road, Barrow-in-Furness||12 April 1921|
|NLB/60/877||Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to S. B. Gaythorpe Esquire; 3 Prospect Road, Barrow-in-Furness||20 April 1921|
|CLP/3i/56||Paper, 'Anagrammata' by Christian Huygens||4 September 1669|
|CLP/3i/45/3||Diagram, the motion of bodies resulting from impact by Christian Huygens||1668|
|CLP/3i/45||Paper, 'De motu corporum ex multuo impulsu' [On the motion of bodies resulting from impact] by Christian Huygens||1668|
|CLP/4i/23||Paper, figure of 'pneumaticall engine' by Christian Huygens||28 January 1663|
|EL/H1/30||Christian Huygens, dated at Calais, to Robert Moray ||12 June 1664|
|EL/H1/49||Christian Huygens, dated at the Hague, to Robert Moray ||10 April 1665|
|EL/H1/52||Christian Huygens, dated at the Hague, to Robert Moray ||18 September 1665|
|EL/H1/77||Christian Huygens, dated at Paris, to Henry Oldenburg||10 July 1673|
|EL/H1/87||Christian Huygens, dated at Paris, to Henry Oldenburg||12 October 1675|
|EL/H1/86||Christian Huygens, dated at Paris, to Henry Oldenburg||10 August 1675|
|EL/H1/83||Christian Huygens, dated at Paris, to Henry Oldenburg||8 June 1675|
|EL/H1/23||Christian Huygens, dated at Paris, to Robert Moray ||18 November 1663|
|EL/H1/68||Christian Huygens, dated at Paris, to Henry Oldenburg||22 January 1670|
|EL/H1/67||Christian Huygens, dated at Paris, to Henry Oldenburg||30 October 1669|
|EL/H1/80||Christian Huygens to Henry Oldenburg||15 May 1674|
|EL/H1/42||Christian Huygens, dated at the Hague, to Robert Moray ||2 January 1665|
|EL/H1/38||Translation of a letter from Christian Huygens to Robert Moray ||1664|
|EL/H1/36||Extract of a letter from Christian Huygens, dated at the Hague, to Robert Moray ||1664|
|EL/H1/81||Christian Huygens, dated at Paris, to Henry Oldenburg||30 January 1675|
|NLB/61/407||Copy letter from Francis Alexander Towle, Assistant Secretary of the Royal Society; to S. B. Gaythorpe Esquire; 3 Prospect Road, Barrow-in-Furness||2 July 1921|