ABSTRACTS OF SCIENTIFIC PAPERS 369 



engines referred to, and a full illustrated account of the operation 

 of the valves of Otto's engine : (4) a Report by Dr. Slaby in which 

 the Lenoir and Otto engines are compared and experimental data sup- 

 plied : (5) an excerpt from Dr. F. Grashof's work on the Mechanical 

 Theory of heat, giving physical constants relating to coal-gas and its 

 combustion : (6) particulars of Mr. J. E. Dowson's cheap gas as fuel 

 for gas engines : and (7) the Patent Specification of R. and J. Stirling 

 for air engines (1827). 



XXXIX. Telpherage, being the introductory address to the Class of 

 Engineering in the University of Edinburgh for the Session 

 1883-4, October 30, 1883. ' The Electrician,' November 3, 1883 ; 

 ' La Lumiere Electrique,' November 10, 1883. 



XL. Telpherage, being the substance of a lecture delivered at the 

 School of Military Engineering, Chatham, on March 13, 1884. 



XLI. Telpherage, A paper read before the Society of Arts, May 

 14, 1884. 'Journal of the Society of Arts,' May 16, 1884. 



These papers refer to the invention the development of which 

 formed Professor Jenkin's last work. Arts. XL. and XLI. are 

 substantially identical. A reprint of the latter is given at p. 252. 



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