CHAPTER IV[ToC]
ON THE USE OF THE FILE
The most necessary tool in a machine shop is a file. It is one of the neglected tools, because the ordinary boy, or workman, sees nothing in it but a strip or a bar with a lot of cross grooves and edges, and he concludes that the only thing necessary is to rub it across a piece of metal until he has worn it down sufficiently for the purpose.
The First Test.—The fact is, the file is so familiar a tool, that it breeds contempt, like many other things closely associated in life.
Give the boy an irregular block of metal, and tell him to file it up square, and he will begin to realize that there is something in the handling of a file that never before occurred to him.
He will find three things to astonish him:
First: That of dimensions.
Second: The difficulty of getting it square.