50 Britain's Heritage of Science 



Cambridge, and subsequently was elected Professor of 

 Astronomy at Gresham College. He returned to his Alma 

 Mater in 1663 to take up the newly-founded Lucasian 

 Professorship of Mathematics. Perhaps he performed his 

 most noteworthy scientific act when he resigned his chair 

 in favour of his pupil Newton. 



John Wallis (1616-1703) is another example of a Univer- 

 sity Professor who took an active share in the national life. 

 After passing through Cambridge, where like Barrow he 

 studied medicine, he took Holy Orders in 1641, but became 

 involved in politics; he attained considerable facility in 

 deciphering intercepted despatches of the Royalists, and 

 thereby rendered considerable service to the Puritan party. 

 After holding several livings in succession, he was appointed 

 Savilian Professor of Geometry in 1649, in spite of the 

 opposition of the Independents, who resented his having 

 signed the protest against the execution of Charles I. John 

 Wallis was one of the foremost mathematicians of his time. 

 His work dealt chiefly with applications of Descartes' 

 analytical geometry; but he also published a book on 

 algebra. He seems to have been the first to conceive the idea 

 of representing geometrically the square root of a negative 

 quantity, and is the originator of the sign oo for infinity. 

 Other writings of his dealt with the tides. His efforts to 

 teach deaf mutes to speak, which are said to have been 

 successful, were the first attempts in that direction. Wallis 

 was also interested in investigations on sound, and in a paper 

 published in the Philosophical Transactions he communicated 

 some interesting experiments made by William Noble, 

 fellow of Merton College, and Thomas Pigot, Fellow of 

 Wadham, which contain important investigations on the 

 phenomenon of resonance in sound. Light bodies were 

 placed as riders to investigate the vibrations of stretched 

 wires, and it was shown that when these wires responded 

 to a higher harmonic, the riders were not set in motion if 

 placed at what we now call the nodal points. 



Associated with the group of mathematicians who were 

 contemporaries of Newton, Lord Brouncker (1620-1684) 

 takes an intermediate place between the professional and 

 non-academic class. The title descended to him from his 



