PLATES. 



I. Illustrative of Prof. Wiedemann's Magnetic Researches. 



II. & III. Illustrative of Prof. R. Shida's Paper on a New Instrument 

 for continuously recording the Strength and Direction of a 

 Varying Electric Current. 



IV., V. ; VI. Illustrative of Prof. S. P. Langley's Paper on hitherto unre- 

 cognized Wave-lengths. 



VII. Illustrative of Mr. T. Gray's Paper on the Electrolysis of Silver and 

 of Copper. 



VIII. Illustrative of Prof. Cornu's Paper on the Distinction between 

 Spectral Lines of Solar and Terrestrial Origin. 



