The Optical Magic Lantern Journal (January 1893)

The Optical Magic Lantern Journal and Photographic Enlarger. 3 T and G are open, the gas that is being generated will find its way into the cylinder I and to the gauge H, and by the time the mixture that was placed in the retort has been exhausted, a pressure of about 65 lbs. should be indicated by the gauge. The cessation of gas being generated will be appazent by the stoppage of the bubbling sound in the washing bottle, when the valve F should be closed. The retort may then again be charged, first disconnecting the union 1; and washing out with water whilst warm, and then placing in it about one half of the previous charge, and heating as before. open, but F closed until the pressure indicated on the gauge indicates a little more than that shown as being the conterts of the cylinder (say 68 or 70 Ibs). ‘The valve F is now opened and the cylinder allowed to fill until about 100 Ibs. are represented on the gauge. In order to relieve any sudden pressure that may occur, a ‘ blow-out” is placed at B. This consists of a thin metallic dise which will bend and blow-out at a pressure of 200 Ibs. to the square inch. Should there by any means be a greater pressure of gas at the cylinder than at the retort there would be a tendency to force the water from the wash bottle D into the hot retort, but as this would be decidedly undesirable, a check valve C is placed on the tube between the retort and the washing bottle. This valve will allow of a free passage from the retort, but immediately closes with the slightest back pressure. When the cylinder is filled it is disconnected at the T piece, and into its place is screwed the necessary connections for the lanterns. —_:0:——_Aphengescope and Vertical Attachment in One. By Cruaup §. Scott. I HAVE read with interest and profit the article on aphengescopes which appeared in the November number of The Optical Magic Lantern Journal, and have pleasure in giving a descrip The valves E and G are allowed to be | tion of a special form of aphengescope which I ! have in use. This form answers the double purpose cf an, aphengescope for a bi-unial lantern, and also a vertical attachment. Having found it very useful I will give such details as will enable any mechanically-inclined readers to construct it for themselves. The apparatus consists of a rectangular | wooden box with a base board attached, open at the bottom. At the back are two circular holes, shown at AA, Figs. 1 and 2, to receive the nozzles of a bi-unial lantern (not shown), which is placed at the back of the apparatus. When used as an aphengescope (Fig. 1), the two mirrors, B B', are placed opposite the open ings, A A’, as shown ; the mirrors are hung upon pins, and can be set at the proper angle by means of set screws working in radial slots on the right-hand side of the apparatus. These mirrors reflect the light from the lantern upon the object, C, which is held by a carrier on the small door, D, at the back of the apparatus. The objective is screwed into a flange on another door, 5, on the front, and opposite the object C. When used as a vertical attachment (Fig. 2), the condenser, F, from the top lantern is placed in a suitable frame above the bottom mirror, B', (this frame can be removed when the apparatus is used as an aphengescope), the mirror is then adjusted so as to reflect the light from the bottom lantern through the condenser, F. The object, C, being placed on a glass stage plate immediately above the condenser, F. At the sidcs of the apparatus are doors, G G, which can, if necessary, be removed, leaving an opening for any object to be placed upon the glass stage plate. The door E (Fig. 1), with the objective is removed, and placed at the top as shown (Fig. 2), its place being filled with the door E!, which is made interchangeable with it.