The combination square provides a means for[p. 19] doing a great variety of work, as it combines the qualities of a rule, square, miter, depth gage, height gage, level and center head.
The full page illustration ([Fig. 11]) shows some of the uses and the particular manner of holding the tool.
Micrometers.—Tools of this description are made which will accurately measure work in di[p. 20]mensions of ten-thousandths of an inch up to an inch.
The illustration ([Fig. 12]) shows an approved tool, and this is so constructed that it can instantly be changed and set by merely pressing the end of the plunger as shown.
Protractors.—As all angles are not obtainable by the square or bevel, a protractor is a most desirable addition to the stock of tools. As one side of the tool is flat it is convenient for laying on the paper when drafting, as well as for use on the work.