C V ] 
LTST OF ILLUSTRATIONS. 
Plate 1.—Dr. Louis Vessot King on the Propagation of Sound in the Free Atmo¬ 
sphere and the Acoustic Efficiency of Fog-signal Machinery. 
Plate 2.—Prof. A. Fowler and Mr. C. C. L. Gregory on the Ultra-violet Band of 
Ammonia, and its Occurrence in the Solar Spectrum. 
Plates 3 and 4.-—Mr. George W. Walker on Surface Reflexion of Earthquake 
Waves. 
