Fig. 154 shows creosoted wooden pipes; Fig. 155 shows another form of wooden pipe. Fig. 156 shows a coupling-box used to join Edison tubes. The three wires, used in the three-wire system, are insulated from each other, the whole being surrounded by an iron pipe of convenient length for handling. Fig. 157 shows sections of man-holes and various devices used in conduit work.
Fig. 163.
141. Miscellaneous Appliances. When the current enters a house for incandescent lighting purposes, for example, quite a number of things are necessary. To measure the current a meter is usually placed in the cellar. In new houses the insulated conductors are usually run through some sort of tube which acts as a double protection, all being hidden from view. Fig. 158 shows a short length of iron tube with a lining of insulating material. Wires are often run through tubes made of rubber and various other insulating materials.
Where the current is to be put into houses after the plastering has been done, the wires are usually run through mouldings or supported by cleats. Fig. 159 shows a cross-section of moulding. The insulated wires are placed in the slots, which are then covered.
Fig. 164.
Fig. 165.
