45, COENHILL, E.G., AND 122, EEGENT STREET, W., LONDON. 



147 



1 FIG. 190. 



FIG. 189. 



FIG 192. 



189 Storm Glass or Chemical Weather Glass, for prognosticating Each. Each. 



changes in the weather, by sea or land, particularly 



high winds, storms, or tempests (fig. 189) . . .046 056 



190 Ditto ditto mounted on a Boxwood Scale, with 



a Thermometer (fig. 190) . . . . 7s. 6d. 10 6 12 6 



191 Ditto ditto . . plain Window Bracket . 12 6 



192 Ditto ditto best, mounted on Window Bracket(fig. 192) 110 1 15 

 This curious instrument appears to have been invented more than a hundred 



years ago. The original maker is not known; but doubtless it is an accidental 

 discovery of some of the old Alchemists, who were constantly experimenting with 

 the substances composing the solution with which it is made. It is simply a long 

 glass vial, nearly filled with an alcoholic solution of camphor, to which is added 

 crystals of nitrate of potassa and muriate of ammonia, with a small proportion of 

 distilled water. Air fills the upper part of the vial, the mouth of which is corked 

 or hermetically closed. 



The various appearances presented in the liquid and crystals have been 

 noticed to prognosticate atmospheric changes, and rules have been deduced from 

 careful study and comparison of the glass and weather. Instructions for using 

 the Chemical Storm Glass sent with each instrument. 



Admiral Fitz-Roy, in The Weather Book, writes of this instrument as follows : 



"Since 1825, we have generally had some of these glasses, as curiosities rather than otherwise; for 

 nothing certain could be made of their variations until lately, when it was fairly demonstrated that if fixed 

 undisturbed in free air, not exposed to radiation, fire, or sun, but in the ordinary light of a well- ventilated 

 room, preferably, or in the outer air, the chemical mixture in a so-called storm-glass varies in character with 

 the direction of the wind not its force, specially (though it may so vary in appearance, only from another 

 cause, electrical tension)." 



Some curious information connected with the Camphor Glass will be found in two 

 pamphlets written by Charles Tomlinson, Esq., of King's College, London, on The Move- 

 ments of Camphor on Water, and The Motion of Camphor towards Light. From these papers 

 it would appear that the changes observed in the Storm Glass are due solely to variations 

 of light and heat. 



L 2 



