A. Williamson, C. Wheatstone 147 



whose brilliant career was cut short by premature death, may 

 here be referred to. William Kingdon Clifford (1845-1878), 

 second wrangler in 1867, held the Chair of Applied Mathe- 

 matics during eight years, but was stricken with tuberculosis, 

 and died in Madeira. He has left many important con- 

 tributions both to applied and pure mathematics. 



Among the Professors at King's College appointed at 

 or shortly after its foundation were two men of world-wide 

 reputation, John Frederick Daniell (1790-1845) and Charles 

 Wheatstone (1802-1875). Daniell constructed the first 

 electric cell which was free from the irregularities caused by 

 polarization, so that constant currents could be obtained. 

 He was mainly interested in meteorology, and rendered 

 valuable services in insisting on accurate and systematic 

 observations of the various phenomena on which the physics 

 of the atmosphere depends. His most successful instrument 

 was that by means of which the humidity of the air is 

 determined from the temperature at which dew begins to 

 deposit. 



Wheatstone began his career as a maker of musical 

 instruments, and during the ten years 1823 to 1833 

 published a number of papers on sound. In 1831 he was 

 appointed to the Chair of Natural Philosophy at King's 

 College, and three years later conducted some experiments 

 which were devised to measure the velocity with which 

 electrical effects are transmitted along a wire, and the 

 duration of an electric spark. In these experiments a rotating 

 mirror was first used to measure small intervals of time. 

 He was also one of the first to recognize the importance of 

 Ohm's law, and to insist on accurate standards and good 

 methods of measuring electromotive force, resistance and 

 current. The Bakerian Lecture for 1843 contains a descrip- 

 tion of the methods employed by him, including the arrange- 

 ment of wires now familiar to every student of science 

 under the name of the " Wheatstone bridge." As he points 

 out himself, the arrangement was first used by Samuel 

 Hunter Christy (1784-1865), Professor of Mathematics at the 

 Military Academy, Woolwich. 



Wheatstone was the first to show how a number of clocks 

 can simultaneously be regulated by the electric current. 



K 2 



