45, COBNHILL, E.G., AND T22, REGENT STREET, W. ; LONDON". 



227 



FIG. 760. 



744 



FIG. 744. 



FIG. 761. 



Each. 

 s. d. 



056 



15 



1 10 



Set of Five Lenses of various forms and curves, 

 (fig. 744), with a small Prism to illustrate the Science 

 of Optics, in a hinged case ...... 



745 Model of the Human Eye, showing the position of 



various humours and Lenses, and for demonstrating 

 the cause of Presbyopia or Long Sight ; Myopia, Short 

 or Near Sight, &c., &c. In Mahogany Box 



746 Kaleidoscopes, with two or three reflecting planes 2s. 6d. 



Ditto ditto, on Table Stand 7s. 6d., 10s. 6d. 



747 Chromeidoscope, a modification of the Kaleidoscope 



748 Debuscope, or Table Kaleidscope, with Plated Metal 



Reflectors 



749 Spectroscope, for Chemical research. See Chemical 



Section 



750 Photometers, Wheatstone's 



751 Ditto for Gas Testing . . See Chemical Section 



752 Radiometer, Crook's . . . ditto ditto 



753 Goniometer, Wollaston's, for measuring the angles of 



Crystals ......... 



754 Anorthoscope, with twelve diagrams (fig. 725) 



755 Praxinoscope, a novel and pleasing arrangement of the 



above with six coloured pictures . . . 16s. 



756 Polemiscope, by means of which any object may be seen, 



though an opaque body be placed before it 



757 Phantascope, for exhibiting the illusion effected by a 



concave mirror, projecting figures in air . 



758 Polyorama, with six views, so constructed that day and 



night effects are produced by means of reflected and 

 transmitted light 



759 Videoscope, for Reading, Drawing, Engraving, &c., 



having a clamp to screw the Instrument to the table, 

 with joint and sliding adjustment with clamp . 



760 Visuometer, Photographic (fig. 760), for enabling the 



artist to judge the effect of a landscape, folding for 

 the pocket ......... 



761 Focussing Glass, Photographic (fig. 761), for obtaining 



a perfectly sharp image on the focussing Screen of 

 the Camera ......... 



Lenses or Prisms of all kinds made to order. 



Models and Diagrams to explain and demonstrate the Elementary 

 Optics, the Theory of Vision, the construction of Refracting and Reflecting 

 Simple, Compound, and Solar Microscopes, &c., &c, supplied to order. 



Q 



150 



12 6 



Each 

 s. d. 



150 1 16 



6 

 1 10 

 110 

 220 



10 6 



2 10 330 



550 

 220 



1 15 

 330 

 440 



220 



1 10 6 

 046 



16 



Laws of 



