ADVERTISEMENTS. 



TEE YICTORIA ELECTRIC THERMOMETER. 



This instrument is very sensitive, phowing llie slightest chaDge of temperature, and may be 

 fully relied upon for all the purposes of a 



THERMOMETER, ALARM, OR INDICATOR. 



Extract from the GABDENERS' CHRONICLE, JVoventber 5, 1870. 



" This invention consists in the adaptation of a peculiar form of balance thermometer, 

 designed by the patentee, Mr. G. liothuie, to the purpose of conneciiDg together separate 

 wires, in connection with a galvanic battery. The action of the instrument is the res^ult of 

 the expansion of spirit, which occupies the upper part of the tube, and rests on quicksilver in 

 the lower part. This latter, by the expansion or contraction of the spirit, is displaced at one 

 end of the tube and driven nver to the other, as the brat or cold may predominate, and thus 

 overbalancing the tube, makes it descend so as to come into contact with the pillars on either 

 side of the stand, as the case may be. 



" To show more clearly what is the power and sensitiveness of this instmment, let us see 

 what it will effect. Take 1" of heat; this, even to the most sensitive person, would be 

 imperceptible; aided by a common thermometer we might just perceive it. Applied to a 

 long glass tube, filled with quicksilver, it will only expand the metal in that tube l-9990th 

 part— or, in other words, a tube filled with qnicksiher, 52 feet high, for 1" of additional heat 

 will expand upwards 1-I6th of an inch. Taking one of the most expansive of fluids— air— a 

 tube 6 teet high, filled with atr, will expand l-8th of an inch in height, since air expands at 

 the rate of l-49fith for one degree of heat. Now, the effect of one degree of heat on the Victoria 

 Thermometer will be to cause it to ring a large bell upwards of IW miles off." 



VJUTUUIA iiLbCTRlU THi.RMu.V„..--K. 



Extract from the Gardeners' JIAGAzine, /November 26. 1870. 

 "The VICTORIA ELECTRIC TUERMOMETER, invented by Mr. Rothnie. and lately 

 presented to public notice by Mr. B. S. Williams, of the Victoria Nursery. Upper Tlolloway, 

 merits attention for its admirable ada]>tntion to all the purposes of a ' tliermostat,' without 

 any of the objections usually arising in connection with the use of such an instrument. The 

 inventions of Dr. Ure and J)r. Arnott were in principle alike throughout, though various in 

 form and material. The ' Victoria Electric Thermometer' is certainly one of the best of the 

 latest inventions of this class ; most likely the best, because of its universal applicability.". 



Price of TheTmometer only £1 10s, 



Price of Thermometer, incttidiTUf Galvanic Battery, Two Electric Betls, Jndicatoi; Walnut-tcood 

 Stand, and all jisc^ssary connections, can be supplied on application to 



B. S. WILLIAMS, 



YintnTin and PararliRft WnTspripq. TTnTifiT Hnllnwa.T. London. 5. 



