45, CORNHILL, E.G., AND 122, EEGENT STREET, W., LONDON. 487 



FlG. 2975. FIG. 2991. 



Each. Each. 



2975 Stands for Reflectors, best make, with jointed adjust- 



ments (fig. 2975) per pair 2 12 6 



2976 Ditto for Iron Ball, &c. 086 



2977 Parabolic Conjugate Reflectors or Mirrors, 18 inches diameter, Stout 



Silvered Copper, mounted on adjustable Stands, with Iron Ball 



and Stand 10 10 



2978 Leslie's Radiator, or Cube, small size .... 056 



2979 Ditto ditto larger, with adjusting Stand . . 15 110 



2980 Leslie's Radiator is a square tin vessel, each of the four side surfaces being 



different. One is left bright, one roughened, one dull white, and the other 

 black. The vessel being filled with boiling Water the various surfaces will 

 be found by the use of Leslie's Differential Thermometer (No. 2952) to 

 radiate or give off varying amounts of Caloric. 



2981 A Set of Three Leslie's Cubes, each having inserted a delicate Thermometer 



for noting the rate of cooling of the liquids in the vessels dependent 

 upon their exterior surfaces. Price, for 3 best mounted Cubes 2 10 



2982 Leslie's Pyroscope, for ascertaining the comparative 



radiation of various bodies 1 10 6 



2983 Ditto ditto an improved arrangement (fig. 2983) 



as described by G-anot 330 



2984 Radiation, Reflection, or Absorption of Heat Apparatus ; consisting 



of two flat metal discs, having one side blackened and the other 

 bright, with small cups or shelf for holding pieces of Phosphorus. 

 These discs being placed at equal distances from a heated Iron 

 Ball, the Phosphorus will be inflamed on the black surface, 

 whilst that on the bright one will remain imchanged . . . 18 (> 



2985 Boutigny's Experiment for exhibiting the spheroidal condition of 



water when in contact with a strongly heated surface, and also 



the non-conducting power of vapour . ... . ." .330 



2986 Silver Bottle !and Stopper, for exhibiting the sudden evolution 



of steam in Boutigny s experiment 220 



2987 Apparatus to show the Imperfect Conducting Power of Water, 



consisting of a sensitive Air Thermometer, so arranged that Ether 

 can be ignited upon the surface of water surrounding the air bulb, 

 without producing any movement in the thermometer . .110 



2988 U Shaped Glass Tubes, for illustrating Convection . . .050 



2989 Faraday's Convection Apparatus, best form, on a stand, for illustrat- 



ing the mode of heating buildings, &c., by hot water . . . 18 



2990 Tyndall's Geyser Apparatus, of large size, with Zinc Trough and 



Copper Corners 700 



