XI. APPLICATIONS. 325 



1698. Battery Case, containing six large Meidinger's cells 

 for working the above apparatus. C. $ E. Fein, Stuttgart. 



1699. Lamp -with Double Screen, slide and adjustable lens, 

 scale stand, scale, &c. To be used with reflecting galvanometers 

 generally. Elliott Brothers. 



1700. Magneto-electric Railway Block and Day and 

 Night Signalling Apparatus. Geminiano Zanni. 



1701. Magneto-electric Morse Ink Printing Tele- 

 graphic Apparatus. Geminiano Zanni. 



1702. Magnetic Bells and Signals. Geminiano Zanni. 



In the above the mechanical electric bell moved by clockwork, at present in 

 use, is dispensed with. The motion of the coils is caused by moving a bell-pull 

 lever half a revolution. Self-acting apparatus may, by this invention, be 

 arranged for giving alarm in case of fire or burglary ; by adopting clockwork 

 to set the coil in motion, the bell or signal would act on opening a door or 

 window, or by the heat resulting from fire. 



1702 a. Electrical Alarum with Leclanche's Battery. 



Mariais, Paris. 



This apparatus consists of a watch placed on a box which contains an 

 electrical bell worked by two elements of a chloride of ammonium (called 

 Leclanche's battery). The wire from the zinc is fixed in the binding screw 

 No. 2, the wire from the carbon in the binding screw No. 1. When the small 

 hand of the watch touches the piece which turns in the circular groove, the 

 bell rings until the hand is released by turning the small handle which is at 

 the side of the piece. The binding screw No. 3 which is above is to be used 

 for the wire from the carbon when the apparatus is used as an ordinary electric 

 bell. The polished stem which carries' No. 4 binding screw can only be used 

 for six hours, when the rod which carries the platinum point is clamped in 

 the hole. 



1702b. Lamp with Self -lighting Electrical Apparatus 

 and Bichromate of Potash Battery. Mariais, Paris. 



The battery inside is charged with bichromate of potash mixed with about 

 one-tenth water. The lamp, the small tube of which can be seen, is an ordinary 

 benzolin lamp with sponge ; when once filled it is put in its place. By pressing 

 on the central button the lamp is made by the mechanism of the apparatus to 

 approach the platinum lighter (inflamateur), which is in the centre. On letting 

 the button go, the lamp is lighted. The cover of the lamp should be replaced 

 by the hand in order to prevent evaporation. 



The box contains eight spare platinum plates. 



1703. Pair of Undemagnetizable Coils, designed in 1866. 



S. Alfred Varley. 



The magnetic needles inside these coils are made of soft, iron rendered 

 magnetic by induction, instead of being made of tempered steel magnetized. 



As the needles are magnetic only by virtue of the permanent magnets in 

 their neighbourhood, the influence of powerful currents, induced by lightning, 

 upon them, can only be momentary ; consequently the telegraphic circuit is 



