208 



L. CASELLA'S CATALOGUE 



DISSECTED CONES, PAINTED BLACK. 



2426. CONE, containing the ellipse, parabola, and hyperbola, 3-inch, base 



2427. ,. 5 



2428. ., ,f 



base . 



030 



> 060 



triangle and circle, 8-inch. 

 110 



2429. GONIOMETEB, PEPYS'S, for measuring the angles of crystals, in case, for the 



pocket . ..110 



2430. GONIOMETEB, for measuring the angles of crystals . . 3 15 



2431. GONIOMETER, WOLLASTON'S, reflecting . . . . 550 



FIG. 2432. 



WORKING MODELS OF STEAM ENGINES, 

 STEAMBOATS, ETC. 



The following list includes only such models as are carefully tested, and the fullest 

 confidence may be placed in their working with perfect efficiency. The marine engines 

 named (or larger sizes) can be applied to suitable working model ships if required. 



2432. Marcel's Steam Apparatus, with barometer, thermometer, stop-cock, etc., for 



illustrating the principal experiments connected with high or low pressure 

 steam and latent heat (Jig. 2432) . . 400 and 4 10 



2433. Locomotive Engine, 18 inches long, boiler heated by charcoal or spirit lamp, 



with fixed cylinders, slide valves, tubular boiler, steam cocks, for high and 

 low water-marks, water gauge, steam whistle, safety valve, lamp, spring 

 buffers, etc., best make ... . 30 



2434. DITTO, DITTO, as above, with reversing gear . . . 36 

 2434*. TENDER for the above, with spring buffers . . . 400 



