Electric Wiring - Instruction Paper #250162

Another form of rigid conduit is that known as the armored con duit, which consists of iron pipe with an interior lining of paper impregnated with asphaltum or similar compound. This latter form of conduit is now rapidly going out of use, owing to the unlined pipe being cheaper and easier to install, and owing also to improved methods of protecting the iron' pipe from corrosion, and to the introduction of additional braid on the conductors, which partly compensates for the.