739 



WILLIS, REV. ROBERT. 



WILLIS, THOMAS. 



740 



to construction and decoration, especially of the peculiar style (from 

 which it eeems impossible now to disappropriate the in every way 

 incorrect appellation of Gothic) that was brought to BO high a degree 

 of perfection in the ecclesiastical edifices of this country. On account 

 of his eminence in the science of construction, he has been made an 

 honorary member of the Institution of Civil Engineers and of the 

 Royal Institute of British Architects. 



He communicated papers to the Cambridge Philosophical Socioby 

 in 1828 and 1829 ou the vowel sounds, and on reed organ-pipes, 

 extending and greatly improving the experimental researches of 

 Kratgenstein and Kempelen ; and on the mechanism of the larynx. 

 These were inserted in vols. iii. and iv. of the society's ' Transactions,' 

 and one of the subjects treated in the former paper was afterwards 

 analytically investigated by Mr. Hopkins in a paper in vol. v. 



In 1831 he produced an acoustic machine called a Lyophone, by 

 which he showed that the sound given by such instruments as the syren 

 of Cagniard de la Tour aud the earlier similar instrument of Robison 

 is caused, not by the periodical interruption of the current of air, but 

 by the close recurrence of small noises. Being an original member of 

 the British Association for the Advancement of Science, he was 

 requested by the Committee of Mathematical and Physical Science, of 

 which also he was a member, to prepare a Report on the state of our 

 knowledge concerning the phenomena of sound, and the additions 

 which had been recently made to it Of this subject he accordingly 

 delivered an oral account, illustrated by diagrams and experiments, at 

 the second meeting of the Association (Oxford 1832), but the printed 

 report has not appeared, much to the regret of all who are interested 

 in the science of sound. 



Having directed his mind to the philosophy of architecture, in 

 1832-33 Mr. Willis made a rapid tour through France, Italy, and part 

 of Germany, during which two things particularly attracted his atten- 

 tion the undeserved neglect with which the Italian Gothic had been 

 treated, and the influence of locality upon each style of the middle 

 age architecture. It also appeared to him, from an examination of 

 buildings belonging to the period of the introduction of the pointed 

 arch, that it was only one of a great number of new forms then intro- 

 duced into architecture ; and further, that the balance of evidence 

 was in favour of the Saracenic origin of these forms, all of which 

 were used by the Saracens, and some of which, on their first employ- 

 ment by European architacts, were woiked in the Arabian manner. 

 But he found reason to agree with Professor Whewell, that the 

 pointed arch is but one among a vast number of peculiarities which, 

 taken altogether, make up the pointed style ; and he endeavours, in 

 the work embodying these observations (' Remarks on the Architecture 

 of the Middle Ages, especially of Italy,' Cambr., 1835), to push this 

 argument still further, by showing that the peculiarities alluded to 

 were iu all probability the invention of different countries and ages, 

 and that they were combined in various ways together before they 

 finally arranged themselves (by the insensible operation of these suc- 

 cessive combinations upon the minds of the architects, we presume) 

 in that happy order which produced what he terms ' the Complete 

 Gothic.' 



In 1836 Mr. Willis explained to the Cambridge Philosophical Society 

 his views respecting the composition of the entablature of Grecian 

 buildings as distinguished from that feature in the architecture of 

 Egypt. 



The lectures on mechanism which he delivered for the first time 

 to the University of Cambridge on succeeding to the Jacksonian chair 

 in 1837 were based upon a separation of the principles of motion and 

 force new to British science, but which, after having been indicated by 

 Leupold and Monge in distant succession, had been philosophically 

 developed by Ampere in 1834, and was subsequently adopted in this 

 country by Professor Whewell. Professor Willis, in his ' Principles of 

 Mechanism,' designed for the use of students in the universities, and 

 for engineering students generally, published in 1841, pursues this 

 separation into its practical consequences. By a further refinement iu 

 discrimination however in this work, instead of considering a machine 

 to be an instrument by means of which we may change the direction 

 and velocity of a given motion, as had hitherto been done, he has 

 treated it as an instrument by means of which we may produce any 

 relations of motion between two pieces of mechanism. In the preface 

 he intimates the intention of completing his plan of a general work 

 on the science of machinery by applying the considerations of force 

 (in the present volume separated from those of motion), to the combi- 

 nations of which machinery consists, as well as by describing and 

 investigating those parts of machinery in the action of which forces 

 are essential. This design has not yet been accomplished, partly in 

 consequence, very probably, of the publication of Professor Whewell's 

 ' Mechanics of Engineering,' in which he has adopted Professor 

 Willis's views upon the classification of the modes in which motion is 

 communicated from one piece to another of a machine, adding to 

 them the investigation of the effects of forca and resistance ; thus 

 carrying out a portion of the plan necessary to complete this arrange- 

 ment of the science of machinery. In the year 1837 also he exhibited 

 and explained his Tabuloscriptive engine, the object of which is to 

 transfer to paper any numerical series of magnitudes, so as to exhibit 

 the curve obtained by making those magnitudes a series of ordinates, 

 agreeably to the method which has proved so fruitful in the applica- 



tion of analysis to physics, and led to so wide an extension of graphical 

 methods of exhibiting the results. In the same year Professor Willis 

 read a paper on the important subject of the Teeth of Wheels, to the 

 appropriate sectional meeting of the British Association ; and to the 

 corresponding section at the meeting of the following year he 

 explained the Odontograph, an instrument he designed for enabling 

 workmen to find at once the centres from which the two portions of 

 the tooth are to be struck, so that the teeth may work truly together. 

 The investigation of the proper curves to be given to the teeth of 

 wheels had been a favourite occupation with mathematicians of tho 

 highest eminence. The geometry of the subject might in fact be con- 

 sidered to be very nearly complete ; but its application to the require- 

 ments of modern construction appeared to Professor Willis to be 

 susceptible of improvement. In these communications accordingly, 

 and in a paper published, also iu 1838, in the 'Transactions of the 

 Institution of Civil Engineers/ vol. ii., in which the contents of both 

 were embodied, he points out forms possessing properties more general 

 than those which had hitherto been adopted for teeth, as well as some 

 practical methods of tracing readily their outlines, describing and 

 figuring the Odontograph. He incorporated the entire contents of 

 this paper into his subsequent work on the ' Principles of Mechanism/ 

 already noticed, adding to them several original investigations relating 

 to the proportions of the teeth and their least number. 



Professor Willis is also the author of the following works and 

 memoirs : ' On the pressure produced on a flat plate when opposed 

 to a stream of air issuing from an orifice in a plane surface/ Trans. 

 Cambr. Phil. Soc., vol. iii. ; ' On the construction of the Vaults of tho 

 Middle Ages/ and ' On the characteristic iuterpenetrations of the Flam- 

 boyant Style/ Trans, of the Royal Institute of British Architects, 

 vol. i., part 2, 1842; 'A Description of the Sextry-Barn at Ely, lately 

 demolished,' 1843, in the publications of the Cambridge Antiquarian 

 Society; 'Architectural Nomenclature of the Middle Ages/ publi- 

 cations of the Cambridge Antiquarian Society, No. ix., 1844 ; ' The 

 Architectural History of Canterbury Cathedral/ Lond., 1845, on which 

 a ' Critical Dissertation ' was published by Mr. Charles Sandys in the 

 following year; 'The Architectural History of Winchester Cathedral/ 

 1845, and that of 'York Cathedral/ 1816, hi the Proceedings of the 

 Aclueological Institute for those years respectively. All these had 

 been orally delivered at the meetings of the Institute, aud illustrated 

 in the edifices themselves. 'On the Conventual Buildings attached 

 to the Cathedral at Canterbury/ and ' Description of the Ancient Plan 

 [preserved in the library] of the Monastery of St. Gall, in the Ninth 

 Century/ both in the ' Archaeological Journal/ vols. iv. and v., in the 

 latter of which appears a paper by Mr. Edward Smirke, F.S.A., on a 

 passage relating to an important part of the history of St. Stephen's 

 church, Bristol, in Professor Willis's ' Architectural Nomenclature ; ' 

 'An Architectural History of the Church of the Holy Sepulchre/ 

 added to the second edition of Williams's ' Holy City/ Loud., 1849. 



The oral expositions of special subjects in the branches of science 

 to which he has devoted himself, given by Professor Willis to the 

 Cambridge Philosophical Society, to the members of the Royal Insti- 

 tution at their Friday evening meetings, to those of the Royal Institute 

 of British Architects, and at the meetings of the Archaeological Insti- 

 tute, uniting theoretical science of a high order with accurate technical 

 and historical knowledge, have always proved most acceptable to his 

 audiences, especially perhaps those relating to portions of the progress 

 of architecture and to the architectural history of particular cditices, 

 which he has illustrated by pictorial dissected models showing the 

 successive stages of construction of the buildings described. Many of 

 the plates illustrating his works have been engraved from his own 

 drawings, and those accompanying his memoir on vaults exemplify a 

 method he has proposed of indicating to the eye the relative positions 

 as to relief of the elements of their structure applicable to other 

 architectural and engineering subjects. We may trace in his metho Is 

 of investigation and illustration the influence of those adopted by his 

 predecessor Professor Farish iu his lectures, especially of his system 

 of the first principles of machinery, and of the isometrical perspective 

 which he adapted to its graphical representation. 



At Cambridge Professor Willis lectures on mechanics, statics, aud 

 dynamics, with their practical application to manufactures and the 

 steam-engine, and similar subjects. When the late Sir Henry T. 

 De La Beche constituted the Metropolitan School of Science applied to 

 Mining and the Arts, in its present form, he induced Professor Willis 

 to accept the lectureship on Applied Mechanics. In this capacity he 

 gives an extended course of lectures annually, with examinations, 

 imparting to the students those principles of mechanical science which 

 it has formed the business of his life to mature. 



WILLIS, THOMAS, was born at Great Bed win in Wiltshire, on the 

 27th of January, 1621. He received his early education at the school 

 of Mr. Sylvester, in the parish of All Saints, Oxford, and in 1630' he 

 was admitted a member of Christ Church. He took his degree of 

 B.A. in 1639, and that of M.A. in 1642. The civil war having broken 

 out, Willis took up arms in defence of Charles. He does not appear 

 however to have been actively engaged, and he turned his attention to 

 medicine, and took his degree of B.M. in 1646. He then commenced 

 practice in Oxford, and, as was the custom of medical men in his day, 

 regularly attended at Abingdon market. He lived in a house opposite 

 Merton College, and being attached to the worship of the episcopal 



