NEGRETTI AND ZAMBRA, -HOLBORN VIADUCT, E.G., 359 



FIG. 1770. 



1767 Oxy-Calcium Light Dissolving View Apparatus, fitted with condensing 



lenses, 3^-inch diameter, complete with apparatus . . . 14 14s. 



1768 Ditto ditto with Rackw.ork Adjustments (fig. 1768) . . 15 15s. 



1769 Dissolving View Apparatus, fitted with Oxy-Calcium Light, condensing 



lenses, 4-inch diameter, Hackwork Adjustments, complete with apparatus, 



17 17s. 



Argand Oil Lamps are supplied with the above marked thus * for use when the Oxy-Calcium Light is 



not convenient. 



t 



The Lanterns ISTos. 1765 and 1767, and Dissolving Yiew sets 1758 to 1761, can 

 be fitted with the Oxy-Calcium Gas jets (as shown fig. 1776), in place of the Spirit 

 Burners at the same cost. 



The light obtained by this arrangement is almost equal to the Oxy- Hydrogen, 

 and is Quite Safe. Wherever Coal Gas is laid on to the house or building we 

 should advise the use of this jet, being far superior to the Oxy-Calcium ; but where 

 pictures of more than 20 feet diameter are desired, the Oxy-Hydrogen Light 

 must be used. 



THE OXY-HYDROGEN LIGHT. 



1770 Dissolving View Apparatus, illuminated by the Oxy-Hydrogen Lime Light, 



giving a brilliant and distinct picture on the disc 30 feet diameter. 

 Consists of two Mahogany Lanterns with best condensing lenses, 4^-inch 

 diameter, Brass fronts and slide holders, mounted on a stand ; dissolving 

 apparatus^ improved Oxy-Hydrogen Jets and Limeholders ; flexible con- 

 necting Tubes, with stopcocks; gas-bags with Pressure Boards; Hydrogen 

 Generator and Purifier; Oxygen E/etort and Conducting Tubes, &c } 

 complete with Clock Work Motions (best manufacture), adapted to the 

 limeholders, for keeping the lime cylinders slowly revolving and exposing 

 a fresh surface to the action of the gases. The best form of Apparatus 

 for Exhibiting the Photographic Views (fig. 1770) . . . 47 



This Apparatus is supplied either as shown in fig. 1770 or fig. 1765 as may be 

 desired. 



Dissolving View Apparatus, fig. 1768, if mounted with Mahogany Lanterns, 

 as fig. 1770, will be 42s. the pair extra. 



