The frame or base or the lantern is a three-aided square, a little over 6f in. serous, and 13 in. long in internal measurement. It ia closed at the front and open at tbs back of the lantern. It is 2 1/2 in. deep, 7 1/2 in. from ita front; the back condenser board is hinged to a atrip that runs across the top of the frame, and is screwed firmly thereto, flush with its npper surface. A long brass hook f and staple are provided for holding the condensers in place when vertical. The boards are held together, when desired, by mother shorter hook c with staple. The con. dense™ are then in place fur horizontal projection. To arrange them for vertical projection, the email hook c is unfastened, the front condenser H is pushed up until the two are at an serted, resting against the two bottom strips. The mirror should be mounted on a thin board or on a brass plate, so as to provide strength and pro-
A mortice ia cut in the front condenser 6 3/4 in. from its top, 5/6 in. wide and 3; in. long. A piece of board a is cut to slide smoothly back and forward through this mortice. For retaining the atrip in any desired place, a hand screw a is placed on the side of the condenser board, which is notched at both its lower corners. A strip of brass is attached to the side of this atrip for the screw to press against.
The strip carries the slide carrier b and lens C. Thelena is attached to a board about 4 in. wide and 5 1/2 in. high,with a tenon projecting from its base. A mortice is cut near the end of the sliding atrip to receive this tenon.
A second mortice or slot, 4 1/6 in. long and 2 in. wide, is made in the strip a. The slide carrier b is a board 6 1/2 in. high by 4 1/2 in. wide. To its bass ia attached a piece of wood 3 in. square. This is 1/2 in. thick, and below it is a second piece of the same length, bat just 2 in. wide. The second piece enters the slot in the sliding strip a, nnd the slide carrier rests upon the shoulders formed by the upper block. A hand screw d is arranged to hold the slide carrier in place where desired. A smaller movable mirror D is supplied, to be supported above the objective when the lantern is to be used for vertical pro-
A piece of sheet iron is fastened across the bottom of the main frame, on which the lantern E rests. In the front of the same frame a notch is cut in which the piece a rests. To make its position in the front condenser board more eecurc, a second atrip may be attached just below the mortice and to the back of the board. For lantern, any good form of screened lamp may be used. If necessary, a sheet-iron box may be arranged to enclose the source of light ; but with such a lantern as is here shown it is quite unnecessary.
Fig. 54 shows the whole ready for mounting, the lamp being lighted and ready for work. The lamp should, always be lighted before beginning, aa it may take 5 min. for it to attain its full power. Fig. 55 shows the whole put together and arranged for exhibiting views. By removing the slide-carrier, the entire space between condenser and objective it free for the introduction of apparatus or performance of experiments. A soap bubble can be blown and projected in this space. A glass of water can be very prettily shown, and the lantern will be found admirably adapted for the experimenter's use. Fig. 56 shows the lantern arranged for vertical projection, the outline of the mirror being given in dotted lines. As the slide-carrier is not always used for work in this position, it, too, is shown in dotted lined.
If all is properly constructed, the apparatus will be susceptible of all kinds of adjustments. The sliding board a can be moved back and forth in the mortice in the front condenser board,
The slide carrier can also be moved backwards and forwards. By these two adjustments, the slide carrier can be brought to any point desired in the cone of rare converging from the condensers. By moving the lantern backward and forward, any modification in the direction of the light rays emerging from the condenser can be given. A lime light can be used instead of an oil lamp; but as the object was to show a portable lantern, the former has been shown in the cuts. (T. O'Conor Sloane.)
This lamp has no fewer than 5 wicks, hence the name Pentaphane," or 5-fold light. Besides the improvement in the lamp, there are some others not before met with in the ordinary lantern. The shape is somewhat different - the square front carrying the objective being an arrangement for exhibiting opaque objects, which has hitherto been accomplished by a separate piece of apparatus, the aphengeseope, the use of which necessitated altering the position of the lantern, whereas in this case it is effected almost momentarily. For exhibiting transparencies, the objective is screwed into the bottom flange, with a cap screwed in to exclude the light when not in use. The light from the lamp- passea through the condenser in the ordinary way to the objective. When required for opaque objects, such as a C.D.V., medal, works of a watch, etc, etc, all that is required to be done is simply to screw the objective into the top flange. The flat mirror at the bottom is then brought into nse, and fixed at a -proper angle to throw the light from the condenser back on to the object by a piece of metal drilled with a number of holes, and a pin fixed beneath. The object is then reflected through the objective on to the screen.
This arrangement will be found very Serviceable for introducing many interesting objects in the course of an exhibition, which otherwise could not be done without first having them photographed and made into slides in the ordinary way. The 5 wicks of the lamp are arranged parallel, and the light given is, certainly, one of most intense brilliancy and, for transparencies, all that cm be desired for schools or moderate-sized lecture rooms. The difficulty of the accurate adjustment of the wicks, so as to avoid smoke, etc, from so many burners, is obviated by a very simple but, at the same time, very effective arrangement of a fan or shutter placed in the iron chimney of the lamp, which regulates the current of air so that, when the flames are left at a moderate height all level, by turning the fan the current of air is increased, and the combined flames drawn upwards and towards the centre, where the greatest amount of illumi-nation is, of course, required. The lantern appears to be well made ia all its parts; is fitted with 4 in, condensers and portrait combination objective: and is made exceedingly portable, packing into a light iron case only 15 in. by 7 1/2 in. by 13 in., and leaves nothing to be desired by those who wish for a compact and complete instrument ready at a moment's notice.