No. 55418. 



Radiometers and Radiophones. 



649 



55 414. 1 : 2. 



55 416. 1 : 8 



55 418. 1 



Radiometers and Radiophonic Apparatus. 



55.406. Radiometer after Crookes, ordinary pattern 



55.407. idem, with two vanes rotating in opposite directions, Figure 



55.408. - - with aluminium vanes, covered with mica one side 



55.409. with semi-cylindrical vanes (aluminium) . . . 



55.410. - - with hemispherical aluminium vanes 



55,411. Radiometer after Eebenstorff, Figure, with one vane having lengthened surface 

 in order to enable the revolutions to be counted, with wood screen and two wire nets 

 of nickel; also adapted for experiments on Absorption and Eeflection of radiant heat 

 after Freuchen (Ztschr. f. d. phys. u. chem. U., 20, 1907, p. 28) 



55,326. Heat Supply for Radiant Heat, for above, F i g. 55,326, p. 642 



55,412. Radiometer with fixed metal disc (aluminium, copper) and rotary cross above same 

 of transparent mica 



55,413. - - i d e m, with fixed cross and rotating disc above 



* 55,414. Radiophone after Weinhold, Figure (W. D., Figs. 375 and 377 [355 and 357]), 

 apparatus for producing a tone by rapidly repeated radiation, consisting of a plate glass 

 sector disc for the whirling table, and the receiver 



* 55,415. - - i d o m, with a zinc sector disc (W. D., Fig. 376 [356]), fitting the whirling table 

 55,416. Electric Motor with Stand for driving the sector disc, Figure, without disc . . 



55,417. 2 Lenses, bi-convex, 80 mm diam., 500 mm focal length, in mount, on stands for the 

 preceding radiophones (W. D., Fig. 378 [358]) Price, together 



55,418. Radiophone after Mercadier, Figure (M. P., 9 th Edn., II, 2, Fig. 338), with 4 rows 

 of holes giving a chord, keyboard, receiver and sound horn; without wMrling table . 



* Can be used with the projection apparatus. 



Cl. 5157, 

 1952, 1953, 



s. d. 



0. 5.0 

 0.10.0 

 0. 6.0 

 0. 6.0 

 0. 6.0 



0. 10. 



0. 10. 



0. 8.0 



0. 8.0 



0.18.0 

 0.14.0 

 2.14.0 



1. 6.0 

 18. 0. 



1953 1 . 



