RECENT EXPERIMENTS ON FOG-SIGNALS. 273 



rockets proved superior to the syren. On the 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 dis- 

 tance 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 ele- 

 vation which brought it clearly into view, yielded a 

 powerful sound in the face of an opposing wind. 



On the evening of February 9th, 1877, a remark- 

 able series of experiments were made by Mr. Prentice 

 at Stowmarket 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 an- 

 nexed statement contains the name of the place of ob- 

 servation, the second its distance from the firing-point, 

 and the third the result observed. 



Stoke Hill, Ipswich . 10 miles Rockets clearly seen and sounds 



distinctly heard 53 seconds 

 after the flash. 



Melton . . . . 15 " Signals distinctly heard. 

 Thought at first that sounds 

 were reverberated from the 

 sea. 



Framlingham. . . 18 " Signals very distinctly heard, 

 both in the open air and in a 

 closed room. Wind in favour 

 of sound. 



Stratford. St. Andrews 19 " Reports loud : startled pheas- 

 ants in a cover close by. 



Tuddenham. St. Martin 10 " Reports very loud ; rolled away 



like thunder. 



Christ Church Park .11 " Report arrived a little more 



than a minute after flash. 



Nettlestead Hall . . 6 " Distinct in every part, of ob- 

 server's house. Very loud 

 in the open air. 



