RECENT EXPERIMENTS ON FOG-SIGNALS 



289 



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

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

 observed : 



Stoke Hill, Ipswich 

 Melton 



Framlingliam 



10 miles Rockets clearly seen and sounds distinctly 

 heard 53 seconds after the flash. 



15 " Signals distinctly heard. Thought at first 

 that sounds were reverberated from the 



18 



Stratford. St. Andrews 19 " 



Tuddenham. St. Martin 10 " 



Christ Church Park . 11 " 



Nettlestead Hall . 6 " 



Bildestone . 

 Nacton 



Aldboro' . 

 Capel Mills . 

 Lawford 



6 



14 " 



25 " 



11 " 



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 V 13 



