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 



Kramlingham 



Stratford. St. Andrews 19 



Tuddenhum. St. Martin 

 Christ Church Park . 



Nettlestead Hall . 



Bildestone . 

 JTacton 



Aldboro' . 

 Capel Mills . 



Lawfoid 



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 



sea. 

 18 " 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. 



10 " Reports very loud ; rolled away like thunder. 



11 ' Report arrived a little more than a minute 



after flash. 

 6 " Distinct in every part of observer's house. 



Very loud in the open air. 

 6 ' Explosion very loud, wind against sound. 



14 ' Reports quite distinct mistaken by inhabi- 

 tants for claps of thunder. 



25 " Rockets seen through a very hazy atmos- 

 phere ; a rumbling detonation heard. 



11 ' Reports heard within and without the ob- 

 server's house. Wind opposed to sound. 



15} " 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 



