No. 55341. 



Thermal Conduction of Gases. Thermal Radiation. 



643 



55 338. 1 : 6. 



55 331, 55 337. 1:12. 



55341. 2:3. 



Spherical Concave Mirrors, of Gorman Silver, cf. Fig. 55,330/1, special construction, arranged 

 to rotate on firm iron stand, with adjustable Sponge or Bulb Holder, with protecting 

 cover, without Table: 



List No. 



Diameter mm 



Focal Length mm 



Each 



The sponge and bulb holders are now fixed to the mirror mount instead of to the base, in the 

 case of all mirrors from No. 55,328 to 55,332 (see Fig. 55,331). If the position of the mirror is 

 changed the relative position of holder to mirror remains unaltered. 



The mirrors to 300 mm diam. are supplied with a hinged tripod stand, as Fig. 55,330, and the 

 two larger ones with two trunnions on base frame as Fig. 55,331. 



Where a single mirror is ordered, a Sponge Holder will be supplied with same; if a pair of the 

 same mirrors are ordered, a Sponge Holder and a Bulb Holder are supplied. 



Parabolic Concave Mirrors, of German Silver, cf . Figs. 55,330 and 55,331, of special construction, 

 adjustable on firm Iron Stand, with adjustable Sponge Holder or Bulb Holder, with 

 protecting cover, without Table: 



55,334 

 300 

 50 

 2. 12. 



55,335 

 390 

 70 

 3. 10. 



55,336 



500 

 70 

 5. 10. 



1.10.0 



List No. 55,333 

 Diameter mm 250 

 Focal Length mm 40 



Each 2. 4. 

 Get-up: as Nos. 55,328 55,332. 



55.337. Table for setting up Concave Mirrors, see Fig. 55,331, without mirror 



Glass Concave and Convex Mirrors: see Nos. 53,754 53,794, p. 477 and 478. 



55.338. Thermometer on Stand, Figure, for setting up at the focus of the concave mirror, 



from 150 C ' 0. 10. 



55.339. Iron Wire Mantle for glowing charcoal, with shank and stand (M. T., p. 163) . . 0. 10. 



55.340. Platinum Cap (Gauze), with Bunsen Burner, cf. Fig. 55,341, for radiation experiments variable 

 with the thermoscope. Price according to cost of platinum 1. 2. to 1. 8. 



55.341. Platinum Cap alone, Figure (W. D., Fig. 367 [347]), price according to cost of variable 

 platinum 1. 0. to 1. 6.0 



54,950. Thermoscope after Weinhold, Fig. 54,950, p. 588 (W. D., Fig. 368 [348]) ..... 0. 3 



Cl. 5056. 



3421.1932, 41 



