PLATES. 



I. Illustrative of Mr. G. V. MacLean's Paper on the Velocity of Electric 

 Waves in Air. 

 II. Illustrative of Mr. J. Rose-Innes and Prof. Sydney Young's Paper 

 on the Thermal Properties of Normal Petitane. 

 III. & IV. Illustrative of Mr. R. W. Wood's Paper on the Photography 

 of Sound- Waves by the " Schlieren-Methode." 

 V. & VL Illustrative of Dr. J. H. Vincent's Paper on the Photography 

 of Ripples. 

 VII. & VIII. Illustrative of Prof. Fleming and Messrs. Ash ton and 

 Tomliuson's Paper on the Magnetic Hysteresis of Cobalt. 



ERRATA. 



Page 63, 1. 9 below table, for 0-001433 for the thermal conductivity of 

 water read 0-001419, the difference being due to a numerical factor 

 dependent on the B.A. unit having been inadvertently used in the 

 calculation. 

 „ 239, line 19, for oscillator read oscillation which is thus. 



