FORE:"Now where does this come in?" he asked himself. "There isn't a grate in the house that has been touched for years. And this cake is not quite dry yet. And a bit of yellow soap in the tray over the sink that would be as hard as a chip if it had been here since the people left. But it hasn't. Murderer may have washed his hands, which is exceedingly likely, but what did he want blacklead for?"All these things constitute technical knowledge, and the privilege of their acquirement is an element of value. The common view taken of the matter, however, is that it costs nothing for a master to afford these privilegesthe work must at any rate be carried on, and is not retarded by being watched and learned by apprentices. Viewed from any point, the privileges [22] of engineering establishments have to be considered as an element of value, to be bought at a price, just as a ton of iron or a certain amount of labour is; and in a commercial sense, as an exchangeable equivalent for labour, material, or money. In return a master receives the unskilled labour or service of the learner; this service is presumed to be given at a reduced rate, or sometimes without compensation, for the privileges of the works and the instruction received.