Page:Incandescent electric lighting- A practical description of the Edison system.djvu/36

 latter are connected together by the "line wires," the outgoing current wire generally passing forth from the upper brush to the locality to be lighted, from which the wire for the incoming current returns to be secured to the under brush, or what is equivalent to that, the line wires are secured in "binding posts" connected directly to the brushes. We thus have a "closed circuit" as it is generally termed, consisting of the wire coiled upon the armature, the strips or plates upon the commutator, the brushes, and the wire leading from and returning to them, between, or in which the lamps are arranged ; so that the current of electricity generated in the armature, passes through all of these, and returns again to the armature, thus completely traversing what is known as the "lamp circuit."

We also have a line of finer wire passing from one of the brushes, coiling about the field-magnets, and returning to the other brush; this is known as the "field circuit."

The lamp circuit is so named, because