Robison, Desaguliers, Robert Smith 71 



fined to a publication " On the Arithmetic of Impossible 

 Quantities." 



Though but little work of importance was produced at 

 Oxford and Cambridge in the eighteenth century, science 

 was kept alive. John Theophilus Desaguliers (1683-1744), 

 the son of a French Protestant clergyman, who left his 

 country on the revocation of the Edict of Nantes, was 

 brought to England while an infant. He studied at Oxford 

 and acted as Professor of Physics in that University. He 

 settled in London in 1712, and ultimately became Chaplain 

 to the Prince of Wales. After leaving Oxford, he became 

 a voluminous writer on many subjects. In his first paper 

 he describes a new method of building chimneys so as to 

 prevent their smoking. He invented a machine for measur- 

 ing the depth of the sea and other mechanical contrivances. 

 He is best remembered by his electrical work in which he 

 clearly defined the nature of a conductor as distinguished 

 from bodies which could be electrified by friction with- 

 out being attached to insulating handles. He enjoyed a 

 great reputation, being consulted by men of science, and 

 notably by James Watt in connexion with steam engines, 

 having himself introduced some improvements in their 

 construction. 



At Cambridge, Robert Smith (1689-1768), as Plumian 

 Professor, made some valuable contributions to acoustics, 

 published in a separate volume " Harmonics." His great 

 treatise on light contains a wealth of information, and still 

 possesses considerable historical interest. It had a great 

 influence at the time, stimulating the study of optics, more 

 especially with regard to its practical applications in the 

 construction of optical instruments. 



