ADVEETISEMENTS. 



THE TICTORIA ELECTRIC TKERMOMETER. 



This instrument is very sensitive, showing Ihe slightest change of temperature, and may be 

 fully relied upon for all the purposes of a 



THERMOMETER, ALARM, OR INDICATOR. 



Extract from the GARDENERS' CHRONICLE, Jf^ovtmher 5, 1870. 



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

 designed by the patentee, Mr. G. Hothnie, to the purpose of connecting together separate 

 wires, in connection with a galvanic battery. The action of tlie instrument is the result of 

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

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

 end of the tube and driven over to the other, as the heat 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 instrument, 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, tilled with quicksilver, it will only expand the metal in that tubel-9990th 

 part— or, in other words, a tube filled with quicksilver, 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 5 feet high, tilled with air, will expand l-8th of an inch in height, since air expands at 

 the rate of l-49')th 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 lOU miles off." 



VlCJiuKlA KLLCTIUC TllbKiluMKa EK. 

 Extract from the Garden ER-S' magazine, J^ovember 26, 1870. 

 " The VICTORIA ELECTRIC THERMOMETER, invented by Mr. Kothnie, and lately 

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

 merits attention for its admirable adaiifation to all the purposes of a ' thermostat,' without 

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

 inventions of Dr. Ure and Dr. 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 Thermometer only £1 10s. 



Pric*: of Therm orneler, mclwHinr/ Galvanic Battery, Ttco Electric BelU, Indicator, Walnut-fjnood 

 Stand, and all necessary connections, can be supplied on application to 



B. S. WILLIAMS, 



Victoria and Paradise Nurseries, Tipper Holloway, London, N. 



