A process for preserving timber and making it incombustible by impregnating it successively with solutions of iron sulfate and calcium chloride in vacuo.

(historical) A plate prepared by a mechanical process, especially a photomechanical process.

(photography, historical) A photographic process based on the action of light in rendering a thin layer of bitumen, with which the plate is coated, insoluble.

The process of removing moisture from the blast of an iron blast furnace by reducing its temperature so far that it will not remain suspended as vapour in the blast current, but will be deposited as snow in the cooling apparatus. The resultant uniformly dehydrated blast effects great economy in fuel consumption, and promotes regularity of furnace operation, and certainty of furnace control.

The process of washing molten pig iron by adding iron oxide.

A process by which copper matte is treated by passing through it a blast of air, to oxidize and remove sulphur. It is analogous in apparatus to the process of making Bessemer steel.

(engineering, mining) A method of sinking through water-bearing ground, in which the shaft is lined with tubbing and provided with an airlock, work being proceeded with under air pressure.

A process of electric welding in which heat is developed by a large current passing through the metal.

A process of desilverizing argentiferous lead by repeated meltings and skimmings, which concentrate the silver in the molten bath, the final skimmings being nearly pure lead.

A process of tanning goatskin, calfskin or sheepskin, with a combination of vegetable and mineral agents, so that it resembles kid leather.