No. 



Thermal Conductivity. 



639 



55 301. 



55 302. 1 : 5. 



* 55,296. Apparatus for demonstrating the different Thermal Conductivity of copper, lead and 



wood, for steam heating, Figure, arranged for the projection lantern (Fr. phys. 

 Techn., I, 2, Fig. 3859) 



55.297. Copper-Mercury Iodide, for experiments on thermal conduction and thermal radiation 



50 grams 



55.298. Rods of Copper, Brass, Iron, Glass, Wood and 12 small Lead Spheres, after Friedr. 

 C. G. Miiller, for showing different thermal conductivities (M. T., p. 162) 



The spheres are attached to the rods by wax, the ends of the rods being then exposed to heat 

 singly or together, and the pendulum beats being observed. 



5."). 299. Thermal Conduction Apparatus after Looser, with air thermoscopes (Looser, Versuche 

 aus der Warmelehre, 3 rd Edn., p. 131 [2 nd Edn., p. 113]; Fr. phys. Techn., I, 2, Fig. 3867), 

 with 8 bars and octuple thermoseope 



55,300. Apparatus after Wiedemann and Franz, Figure, for Thermal Conduction in Metal 

 Rods, with 6 Rods (M. P., Ill, p. 775 [II, 2, p. 607]; Pogg. Ann. d. Physik u. Chemie, 



3 rd Series, Vol. 89, 1853, p. 501, and 4 th Series, Vol. 95, 1855, p. 337) 



The 6 rods consist of iron, aluminium, zinc, tin, brass and German silver. The measurement 

 is made in vacuo and in an air-filled space by means of a thermocouple. 



* 55,301. Gypsum Slab and Heating Rod, for showing the elliptical Propagation of Heat in 



Crystals, Figure (W. D., Fig. 380 [360]) 



The small gypsum slab coated with paraffin wax is provided with a hole into which is inserted 

 a copper rod which can easily be heated by a flame. A pasteboard screen holds off any disturbing 

 light. The apparatus is used with the horizontal projection apparatus. 



55,302. Apparatus for explaining unequal Thermal Conduction in Crystals, after Senarmont, 

 F i g u r e, with 4 pierced crystal plates, quartz ground parallel to axis, quartz perpen- 

 dicular to axis, calc-spar perpendicular to axis, and gypsum (Fr. phys. Techn. I, 2, 

 Fig. 3829) 



55. .',03. Wood Pyramid with Brass Tube carried through, F i g u i- e, for showing the difference 

 in thermal conduction in wood in a direction along the grain and across the grain (Ztschr. 

 f. d. phys. u. chem. U., 21, 1908, p. 298) 



55303. 



1 : 8. 



s. d. 

 0. 14. 

 0. 5.6 

 0. 4.0 



6. 0.0 



15. 0.0 



0. 5. 



2. 8.0 



0. 5.0 



* Can be used with the projection apparatus 



Cl. 1923, 384-2, 



368, 0131, 1709. 



