But when wire is finished it isn't always finished. Since electricity spread itself over the earth in a million services, insulation in various forms has come to be almost as important as the wire itself. Insulation in its more advanced forms is a complex affair, gauged to accord with specific conditions and multiplying processes to secure the maximum of protection, both from electric current to life and property and from dampness and abrasion to the wire itself. In the making of wire screens the wire men have taken a leaf from the cloth-mill book, but in weaving a casing of cotton or other fibre around the wire for insulation the process is strongly reminiscent of some of the New England textile mills. Long rows of machines, black and silent and swift, reaching upward toward the ceiling, revolving rapidly on an upright shaft; long arms trailing downward, with wheels and bobbins like fingers plying dizzily but swiftly in and out around the wire which unwinds from its spool and keeps forever climbing. It is all like a Maypole, and the bobbins go in and out like children carrying each its ribbon. As the wire climbs, the whirling fingers braid around it a coating, tight fitting and impervious. Sometimes, where double insulation is required, there are two sets of arms, one above the other, the upper one putting on a second covering outside the first, of cotton of one color or another, or hemp or whatever else the experimentalists have found best for the purpose. You wonder how the bellcord in the railroad train can ever stand the pulling and jerking and wear and tear it gets. It is simple. It is just a perfectly made and highly tinned wire rope, with a double coat of braided cotton over it. The jacket may wear off in time, but the Roebling rope inside will never fail in a lifetime to get the message to the engineer. When these snug coverings are finished the wire for certain uses is taken to another part of the works where it is unwound once more to pass through a bath of asphalt compound. After this process, which leaves a dull, dirty-looking surface, the spools of treated wire are put aside for drying, and then a final surfacing applied. The next journey is to the packing room. [Sidenote: TELEPHONE CABLES]