There are large glass, chemical and machine works; nuts and bolts are made, and lighthouse fittings are a specialty.
The iron wire used for wire-netting, telegraphic purposes, &c., is commonly galvanized, as also are bolts, nuts, chains and other fittings on ships.
The principles are the same as those applied to low-pressure work, but all fittings and appliances must, of course, be made to stand the higher strain to which they are subjected.
The system is economical in fuel, but needs skilled attendance to keep the appliances and fittings in order.
The steam mains to the houses are laid by the supply company; the internal pipes and fittings are paid for or rented by the occupier, costing for an installation from £30 for an ordinary eight-roomed house to £Ioo or more for larger buildings.