With the increasing cost of labor and materials effort has been made to salvage and make use of "mill ends" of wire, running sometimes to large quantity, which formerly were accounted waste. These are now passed through a straightening machine, which lays them out in uniform bundles of some ten feet in length, which again may be cut to shorter lengths for special purposes. In the buildings where this is done, at the Upper Plant, are piles of neat bundles of all shapes and sizes and grades, which once went to the scrap for reworking but now are utilized without additional cost. [Sidenote: COPPER WIRE AND COPPER ROPE] Copper wire is manufactured by the Roebling mills in very large quantities and in many sizes and forms, principally for electrical use and for service where water corrosion shortens the life of steel. The little bond wires that link the rails of railways to perfect the carriage of current in the block signal system are mostly steel, but copper is used at stations and on sidings where the leakage from standing cars is apt to contain acids. Copper wire of all sizes down to the very fine is spooled and sold for use in arts and manufactures. For marine uses a deal of copper rope is made, and copper strand is twisted for lightning rods, the fixtures and supports of which, in turn, are manufactured from round and flat steel wire. The piles of this equipment, waiting shipment in the Roebling storerooms, give proof that the satire of the cartoonist and the mockery of the funny writer cannot destroy an ancient faith. The telephone and telegraph companies use uncountable miles of copper wire in line service and other miles in fine sizes for instrument coils and divers other functions. Electricity as an agent would be a halting cripple without wire. The dynamo would have little more utility than a washtub. Armatures, frames for which are formed from flat steel wire, are wound in the Roebling plant in impressive number. One of the largest fields for copper is trolley wires, which are of great size and of many eccentric shapes. This is merely a glimpse at the utilities that go to make up the field for Roebling wire. It is doubtful if today the company owns a complete list of the wire it has made for special and even eccentric purposes, or knows within many thousands the things that are manufactured from its wire product after it leaves the shipping room. [Sidenote: COATING AND FINISHING] Use determines much in the finishing of wire, and of wire rope as well, as not alone concerning the chemistry of the inside, but the covering of the outside. Material that is made for service out of doors, under water or under ground, to ensure long life needs an exposed surface more resistant to moisture than the naked steel. Copper is proof, but the pure wire is expensive for most uses and where severe strains are incurred it lacks in strength. Modern science has been too busy to recover the art of hardening copper which the ancient Egyptians lost.