No. 54 322. 



Stereoscopy. Plastic Vision. Stroboscopy. 



525 



54318. 1:8. 



54 315. 



54 320. 2 : 5. 



54 322. 1 : 5. 



54.317. Schroeder's Step View, as diapositive (W. D. Fig. 312 A [295 A]) for demonstrating 

 the impression of raised and deepened relief 



54.318. Pasteboard Model of the Shroeder Step View, Figure, for facilitating the perception 

 of the different impressions of relief 



* 54,319. Apparatus for imitating the Irradiation of the Moon's Crescent, Figure (W. D., 



Fig. 311 [294]) 



* 54,320. 2 Lantern Slides for demonstrating Irradiation, after Plateau, Figure (M. P., II, 



1, Fig. 291 [388 and 389]) 



54.321. Disc with sectors cut out, for showing the duration of luminous impression in the 

 eye; for the Whiiling Table (W. D. p. 416) 



54.322. Stroboscopic Disc, Figure (M. P., II, 1, Fig. 292 [393]) 



Rotating Mirrors: see p. 431. 



.").'). 179. Stroboscopic Drum (cylinder), see Fig. 53,179, p. 417, with 18 Quincke Wave Strips 



52,019. - - idem, fitting the Whirling Table: see No. 52,019, p. 283 



51'. (120. Strips alone, 18 in all, with description: see No. 52,020 on p. 283 



* Can be used with the Projection Apparatus. 



Cl. 3683, 5516, 

 3397, U88. 



s. d. 

 0. 1.6 



0. 4.0 

 0. 8.0 

 0. 3.0 



0. 6.0 

 0. 18. 



0. 18. 

 0.14.0 

 0. 6.0 



343, 



