Crystal Palace International Electric Exhibition 1881-82

12 [5.] UMSCHALTER SWITCH. This apparatus is used for changing the direction of circuits and for inter-communication purposes. [6.] MODERN SET OF TESTING APPARATUS. Used for examining the electrical condition of the wires. a. Wheatstone’s Bridge and Resistance Coil. b. Astatic Galvanometer. c. Tangent Galvanometer. d. Standard Cell. [7.] NUMBERING- MACHINE FOR NUMBERING- MES- SAGE FORMS. This machine is used to number messages consecutively. The change of number is produced automatically. [8.] TOOL BOX. [9.] MODERN FORM OF TRAIN SIGNALLING- APPA- RATUS. Used for carrying out the block system, by which only one train is allowed in one section at one time. Invented by Pieece, and used on. the South. Western and other l’ailways. [10.] APPARATUS CONNECTED WITH PNEUMATIC TUBES. a. Carriers for pneumatic tubes. b. Specimens of pneumatic tubes, with outer iron pipe. c. Specimens of pneumatic tube after being 25 years in. use. d. Specimen joint in pneumatic tube. . . e. Double Sluice Pneumatic Valve for continuous working. f. Single Sluice Valve for intermittent working. cj. Block Signalling Apparatus for notifying the departure or arrival of carriers. , p h. Terminal Signaller. Automatic signalling appaiatus tor notifying’ the arrival of carriers at the distant station. i. Intermediate Signaller. Automatic. signalling apparatus, to be fixed intermediate upon a pneumatic tube. The duration of the electric contact can be regulated to any required leng h by means of the adjusting screw which limits the admission or air to the cylinder. ... . j. Mandrel used in making joints in pneumatic tubes. fa A Pneumatic Puncker for Wheatstone’s automatic apparatus.