The try-square, Fig. 14, is used for three purposes in general, first, to act as a guide in laying out lines across the grain of a piece of stock, Fig. 15; second, to test the edges, Fig. 16, or ends, Figs. 17 and 18, of a board to see if they make right angles, or are square with the faces; third, to test a piece of stock by sliding the square along it with the eye fixed upon the graduations at the far edge to see whether any change takes place as the square is pushed along, Fig. 19.
Fig. 14. Try-square.
Fig. 15. Lining Across the Grain.
Fig. 16. Testing Edge for Squareness.
Fig. 17. Testing End for Squareness.
Fig. 18. Additional Test of End.
Fig. 19. Test for Uniformity of Width.