444 Sir James N. Douglass on Beacon Lights, &c. [March 15, 



sounding at their maximum power. This is accomplished by the 

 storage of a sufficient quantity of compressed air to work the siren 

 during the time required for raising steam and starting the engine. 

 The signal is thus always in readiness for immediate action, day or 

 niglit, with an expenditure of fuel only incurred during fog, which 

 on the coast of this country does not exceed an average of 440 hours 

 per annum. The experience yet gained with the most powerful fog 

 signals now in use, although these apparatus far exceed in efficiency, 

 for the service of the mariner in fog, any light that science can 

 provide, is not yet so satisfactory as we could desire. The best 

 signal is, as I have already stated, occasionally not heard, under 

 certain atmospheric conditions, beyond two miles ; while under other 

 conditions, not apparent to the mariner, the signal is distinctly 

 audible at ten miles : therefore there is much to be desired in the 

 development of the means of propagating sound waves, and in ren- 

 dering them audible to the manner. In conclusion, I would venture 

 to state that, with the best light and sound signals that can be 

 provided, there are conditions of the atmosphere in which the 

 mariner will earnestly look and listen in vain for the desired light 

 or sound signal, and he must still, under such circumstances, exercise 

 caution in availing himself of their guidance, and never neglect the 

 assistance always at hand of his old trusty friend the lead. 



[J. N. D.] 



WEEKLY EVENING MEETING, 



Friday, March 22, 1889. 



Colonel J. A. Grant, C.B. C.S.I. F.R.S. Vice-President, in the 



Chair. 



Eadweard Muybridge, Esq. 



Tlie Science of Animal Locomotion in its Relation to design in Art, 



(Illustrated by the Zoopraxiscope.) 



[No Abstract.] 



WEEKLY EVENING MEETING, 



Friday, March 29, 1889. 



William Ceookes, Esq. F.E.S. Vice-President, in the Chair. 



A. Gordon Salamon, Esq. F.C.S. 3LBJ. 



Yeast. 

 [Abstract deferred.] 



