RECENT EXPERIMENTS ON FOG SIGNALS. 209 



Shambles light-vessel, when a pressure of 13 Ibs. was 

 employed to sound the syren, the rockets proved greatly 

 superior to that instrument. Proceeding along the sea 

 margin at Flamboro' Head, Mr. Edwards states that at a 

 distance of 1^ mile, with the 18-pounder previously used 

 as a fog-signal hidden behind the cliffs, its report was quite 

 unheard, while the 4-oz. rocket, rising to an elevation 

 which brought it clearly into view, yielded a powerful 

 sound in the face of an opposing wind. 



On the evening of February 9, 1877, a remarkable 

 series of experiments were made by Mr. Prentice at Stow- 

 market with the gun-cotton rocket. From the report with 

 which he has kindly furnished me I extract the following 

 particulars. The first column in the annexed statement 

 contains 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 



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 



Framlingham .... 18 



Stratford. St. Andrews . 19 



Tuddenhatn. St. Martin 10 



Christ Church Park. . . 11 



Nettlestead Hall 6 



Bildestone 

 Nacton 



Aldboro' 



Capel Mills . . . . 

 Lawford - . 



14 



25 



11 



15* 



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 obser- 

 ver's house. Very loud in the 

 open air. 



Explosion very loud, wind 

 against sound. 



Reports quite distinct mis- 

 taken by inhabitants for claps 

 of thunder. 



Rockets seen through a very 

 hazy atmosphere; a rumbling 

 detonation heard. 



Reports heard within and with- 

 out the observer's house. 

 Wind opposed to sound. 



Reports distinct; attributed to 

 distant thunder. 



