RECENT EXPERIMENTS ON FOG-SIGNALS 



289 



tains tlie name of the place of observation, the second its 

 distance from the firing- point, and the third the result 

 observed : 



Stoke Hill, Ipswich . 10 miles 

 Melton . . . 15 '* 



Framlingham 



18 



Stratford. St. Andrews 19 



Rockets clearly seen and sounds distinctly 

 heard 53 seconds after the flash. 



Signals distinctly heard. Thought at first 

 that sounds were reverberated from the 

 sea. 



Signals very distinctly heard, both in the 

 open air and in a closed room. Wind in 

 favor of sound. 



Reports loud ; startled pheasants in a cover 

 close by. 



Reports very loud ; rolled away like thunder. 



Report arrived a little more than a minute 

 after flash. 



Distinct in every part of observer's house. 

 Very loud in the open air. 



Explosion very loud, wind against sound. 



Reports quite distinct — mistaken by inhabi- 

 tants for claps of thunder. 



Rockets seen through a very hazy atmos- 

 phere ; a rumbling detonation heard. 



Reports heard within and without the ob- 

 server's house. Wind opposed to sound. 



Reports distinct : attributed to distant thun- 

 der. 



In the great majority of these cases, the direction of 

 the sound enclosed a large angle with the direction of the 

 wind. In some cases, indeed, the two directions were at 

 right angles to each other. It is needless to dwell for a 

 moment on the advantage of possessing a signal command- 

 ing ranges such as these. 



The explosion of substances in the air, after having 

 been carried to a considerable elevation by rockets, is a 

 familiar performance. In 1873, moreover, the Board of 

 Trade proposed a light-and-sound rocket as a signal of dis- 



SCIENCE — Y — 13 



