Fig. 295.
a. The electric light. b b. The two sets of lenses for the two pictures. c. The dissolving mechanism. d. The picture on screen.
When dissolving views are required on a grand scale, the lenses must be exceedingly large, and the condenser (corresponding with the "bull's-eye" of the simple magic lantern) should be at least nine or eleven inches in diameter, and the front glasses must be of a superior make. The lenses for a large lantern lit by the oxy-hydrogen light, are arranged as in the next cut. (Fig. 296.)
Fig. 296.
a. The lime light. b. The condensers. c. The picture. d d. The front lenses for focussing, with rack-work.
At the Polytechnic the author had no less than six lanterns working at or about the same time, to produce effects, in the views illustrating the voyages of Sinbad the Sailor; and in order to obtain the increased results required for dioramic effects, such for instance as the Siege of Delhi, showing the bursting of the shells, &c., the four fixed lanterns (the fronts of which are shown in the next cut) were always employed. The two upper lanterns are dissolved by discs of brass worked by the hand, and the lower ones with the fans. (Fig. 297.)
Fig. 297.