Lord Rayleigh. 429> 



as third Baron in 1873. He served as Cavendish Professor 

 of Experimental Physics at Cambridge from 1879 to 1884:: 

 he had yielded to the universal desire of his contemporaries, 

 including his intimate friends Stokes and Kelvin, in taking 

 up the duties of the Chair at a critical juncture on the 

 lamented and premature decease of Clerk Maxwell. He was 

 Secretary of the Royal Society from 1887 to 1896 : his- 

 successors in that office recognized many evidences of 

 improvement in method and efficiency that had been effected 

 quietly by him : later for three years he served as President. 

 In the same year 1887 he took up the Professorship of 

 Natural Philosophy at the Royal Institution, which he 

 retained until 1905 ; thereby he had access to a laboratory in 

 London, while his lectures provided a model of how problems 

 strictly scientific could be handled in a manner interesting 

 to an instructed public without any need for adventitious 

 experimental adornment. He was Lord Lieutenant of Essex 

 from 1892 to 1901, and was made a Privy Councillor in 

 1905. From 1896 he was Scientific Adviser to the Cor- 

 poration of the Trinity House, a congenial office in which he 

 had share in many improvements in the lighthouses and 

 sound-signalling apparatus around the coasts. He was one 

 of the twelve original members of the Order of Merit. 



He presided over the committees in charge of the National 

 Physical Laboratory from its first inception under the 

 control of the- Royal Society, until recently when it was 

 taken over in greatly expanded form by the Government. 

 His work in that capacity was of high value in stimulating 

 the zealous assistance of the engineering and other public 

 scientific societies, and still more in guiding the directions 

 of expansion and in pointing out the way to new scientific 

 progress. As Chairman of the Advisory Committee on 

 Aeronautics he contributed probably more than any one else 

 to the opening out of a scientific treatment of the essential 

 problems ot' aereal resistance, especially by development of 

 dimensional theory and the principles underlying experi- 

 ments on models, starting from the stage in which they had 



Phil. Mag. S. 6. Vol. 38. No. 22'). Sept. 1919. 2 (i 



