IV CONTENTS. 



Page 

 Prebce, Professor Schuster, Professor Dewar, Professor Vernon 

 Harcourt, and Professor Atrton, for the purpose of fixing a Standard of 

 White Light 38 



Report on Recent Progress in Hydrodynamics. Part II. — Special Problems. 

 By W. M. Hicks, M.A 1 39 



Report of the Committee, consisting of Professor G. Carey Foster, the late 

 ]Mr. C. HocEiN, Sir William Thomson, Professor Atrton, Mr. J. Perrt, 

 Professor W. G. Adams, Professor Lord Ratleigh, Professor F. Jenkin, 

 Dr. O. J. Lodge, Dr. John Hopkinson, Dr. A. Muirhead (Secretary), Mr. 

 W. H. Preece, Mr. Herbert Taylor, Professor Everett, and Professor 

 Schuster, appointed for the purpose of constructing and issuing practical 

 Standards for use in Electrical Measurements 70 



Eifteenth Report of the Committee, consisting of Professor Everett, Pro- 

 fessor Sir William Thomson, Mr. G. J. Stmons, Sir A. C. Ramsay, Pro- 

 fessor A. Geikie, Mr. J. Glaisher, Mr. Pengellt, Professor Edward 

 Hull, Dr. C. Le Neve Foster, Professor A. S. Herschel, Professor G. 

 A. Lebour, Mr. A. B. Wynne, Mr. Galloway, Mr. Joseph Dickinson, 

 Mr. G. F. Deacon, Mr. E. Wethered, and Mr. A. Strahan, appointed 

 for the purpose of investigating the Rate of Increase of Underground Tem- 

 perature downwards in various Localities of Dry Land and under Water. 

 Drawn up by Professor Everett (Secretary) 72 



Summary of Results contained in the First Fifteen Reports of the Underground 

 Temperature Committee. By Professor Everett (Secretary) 74 



Report of the Committee, consisting of Professor Schuster (Secretary), Sir 

 William Thomson, Professor H. E. Roscoe, Professor A. S. Herschel, 

 Captain W. de W. Abney, Mr. R. H. Scott, and Dr. J. H. Gladstone, 

 appointed for tlie purpose of investigatiug the practicability of collecting and 

 identifying Meteoric Dust, and of considering tlie question of undertaking 

 regular observations in various localities 90 



Second Report of the Committee, consisting of Mr. G. H. Darwin, Professor 

 Sir William Thomson, Professor Tait, Professor Grant, Dr. Siemens, 

 Professor Purser, Professor G. Forbes, and Mr. Horace Darwin, ap- 

 pointed for the Measurement of the Lunar Disturbance of Gravity. AVritten 

 by Mr. G. H. Darwin 95 



Report of the Committee, consisting of Professor Dewar, Dr. William- 

 son, Dr. Marshall AA^atts, Captain Abney, Mr. Stoney, Professor 

 Hartley, Professor McLeod, Professor Carey Foster, Professor A. K. 

 Huntington, Professor Emerson Reynolds, Professor Reinold, Professor 

 Liveing, Lord Rayleigh, Dr. Schuster, and Professor W. Chandler 

 Roberts (Secretary), appointed for the purpose of reporting upon the present 

 state of our Knowledge of Spectrum Analysis 120 



Report of the Committee, consisting of Professors Odling, Huntington, and 

 Hartley, appointed to investigate by means of Photography the Ultra-Violet 

 Spark Spectra emitted by Metallic Elements, and their combinations under 

 varying conditions. Drawn up by Professor W. N. Hartley (Secretary)... 143 



Report of the Committee, consisting of Professor Roscoe, Mr. Lockyer, 

 Professor Dewar, Professor Liveing, Professor Schuster, Captain Abney, 

 and Dr. W. Marshall Watts (Secretary), appointed to prepare a new 

 series of Tables of Wave Lengths of the Spectra of the Elements 144 



Report of the Committee, consisting of Professor Balfour Stewart, Pro- 

 fessor Rucker (Secretary), and Professor T. E. Thorpe, appointed for the 

 purpose of reporting on the Methods employed in the Calibration of Mer- 

 curial Thermometers 145 



