The Optical Magic Lantern Journal (August 1899)

The Optical Magic Lantern Journal and Photographic Enlarger. 97 Years back it was the custom to make. the effect slide containing the moon and _ its reflections on a lever frame, and by raising the handle to disclose the lights by drawing away the blacked out portions of the glass, and this simple motion was found to be sufficient when only the moon and, say, a reflection in the ‘water was needed. But sometimes it was necessary, in order to more perfectly realise the effect, or on account of the position of the prominent objects in the picture, that a small portion of the view upon which the moonlight fell should also be painted on the effect slide in a very light colour, to give the object the appearance of being illuminated by the moon’s rays when thrown upon the main view. In tiis case a frame such as we show at Fig. XXIX. is found useful, and if will be seen that when the lever is in the position. shown in the diagram the moon and its reflections would be disclosed, but on lowering the handle the small portions of opaque black shown by. the dotted lines would descend and cover them, thus cutting the effect off from the screen. If it is desired to cause the moon to actually rise two moving glasses are necessary, one having the moon drawn upon it surrounded by opaque black, and the other, which would be a slip, would disclose the illuminated buildings. In Fig. XXIX. we show one method of causing the moon to rise, and this is in general . Fiz, XXIX, use, as it is easy to make and the frame is inexpensive ; but where excellence of effect is desired, and the small additional expense is not considered an obstacle, a very slow moving rackwork motion offers special advantages. Such a frame we illustrate in Fig. XXX., where we see that it consists of a wooden block 7 inches by 43 inches, with the usual 3 inch glass upon which the view or effect is to be painted set in the centre. Against this set glass rests a larger disc of glass 4 inches in diameter, which has a brass rim with teeth such as we find in the ordinary rackwork slides ; but in this case the teeth of the rack are cut at an angle, and the pinion has an endless worm cut on its diameter. This arrangement moves at a very slow rate of speed compared with the ordinary racks, and enables the operator to raise the moon or sink the sun almost imperceptibly. It will be noticed that the large rack glass is not placed in the centre of the frame as the set glass is, but rather on one side, so that the side of the large glass and that of the small one come close together on the left, but are wide apart on the right. Fig. XXX. This is done to give the moon, which would be on the left side, a more perpendicular path in rising than would be the case were the two circles superimposed. : By arranging the details of our picture in a suitable manner, we may get more than the one effect upon a rack frame. There is a very wellworn subject, which I believe was first copied from Telbin and Grieves’ panorama of the ‘‘Overland Route to India,’”’ representing the arrival of the mail boat at Alexandria, and here we see a dark night scene without a moon, showing only the vessel at anchor and the lights of the town in the distance. The effect to this view is laid out as we see in J'ig. XX XI., where we see the moon, which can be brought on at any time by means of a slip on the other side of the frame, also a ripple, and the steam from the funnel of the steamer. The steam is painted in a small circle in the centre so that it can be revolved without interfering in any way with the moon, and beyond the clear space left for the moon comes the waved marking for causing the ripple on the waves as the glass revolves. The moon