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

plural of process plate

(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.

(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 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.

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.

The process of treating silver ores by grinding in pans or tubs with the addition of mercury, and sometimes of chemicals such as blue vitriol and salt.