PLATES. 



T. Illustrative of Dr. E. H. Cook's Paper on Experiments with the Brush 



Discharge. 



II. Illustrative of Dr. van Pijckevorsel's Paper on the Analogy of some 



Irregularities in the Yearly Range of Meteorological and Mag- 

 netic Phenomena. 



III. Illustrative of Mr. R. W. Wood's Paper on some Experiments on 



Artificial Mirages and Tornadoes. 



