PLATES. 



I. & II. Illustrative of Mr. B. F. W. Bui-stall's Paper on the Measure- 

 ment of Cyclically Varying Temperature. 



III. & IV. Illustrative of Profs. J. Dewar and J, A. Fleming's Paper 

 on the Thermo-electric Powers of Metals and Alloys. 



V. Illustrative of Profs. J. Dewar and J. A. Fleming's Paper on the 

 Variation in the Electrical Resistance of Bismuth, when cooled to the 

 Temperature of Solid Air. 



VI. & VII. Illustrative of Mr. E. H. Griffiths's Paper on the Thermal 



Unit. 



VIIT. Illustrative of Mr. H. Wilde's Paper on Helium, and its 

 place in the Natural Classification of Elementary Substances. 



