ERRATA. 



Page 90 line 21 from top, for thermomftvic read theraio-electric. 



_ 91 _ 31 — piece — pieces. 



98 _ 94 — harmonies — harmonics. 



— 99 — 12 — vibratory — vibrating. 



100 44 — melantic — metaUic. 



_ 101 _ 7 — decline — doctrine. 



_ 183 _ 4 of foot-note on § 12, for more strongly read less 

 strongly. 



PLATES. 



I. Illustrative of Prof. Magnus's Paper on the Motion of Fluids. 

 II. Illustrative of Mr. J. A. Broun's Paper on Electrical Dust Figures. 

 Ill Illustrative of M. E. Wilde's Paper on the Gyreidometer, and of 

 M. A. F. J. Claudet's Paper on the Dynactinometer. 



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