CONTENTS. VII 



PART II. (1847-1878.) 



Programme of organization of the Smithsonian Institution 



On heat, and on a thermal telescope 



On the practical operations of the Smithsonian Institution 



Eemarks on the aurora-borealis .... 



Remarks on the diffusion of vapor 



On the radiation of heat .... 



Remarks on the expansive energy of lightning strokes 



Remarks on the forms of lightning-rods 



On the phenomena of the Leyden-jar . 



On the limit of perceptibility of a direct and reflected sound 



On the theory of the so-called "imponderables " 



The improvement of the mechanical arts. [An address.] 



Thoughts on education. [An address.] 



On the mode of testing building materials, &c. 



On molecular cohesion .... 

 The effect of mingling radiating substances with combustible 



materials ....... (1855) 355 



Experiments on the alleged spontaneous separation of alcohol 



and water ...... 



Remarks on the United States light-house service 

 Researches in sound, in relation to fog-signalling 



Introduction ..... 



Part I. Investigations from 1865 to 1872 



Part II. On some abnormal phenomena of sound 



Part III. Investigations during 1873 and 1874 



Part IV. Investigations in 1875 



Part V. Investigations in 1877 



