Paragraph 10. In boring for mortises, and sometimes in other lines of work, it is necessary to bore holes to a given depth. This is a little difficult unless you have some way of measuring, for it is inconvenient to remove the bit and measure the depth of the hole. Sometimes the shop is provided with a bit gauge, which can be attached to the bit and adjusted to allow the bit to bore any desired depth. If you do not have a bit gauge, a very satisfactory substitute can be formed by boring a hole through any scrap block, then sawing it off to the length which will leave the bit protruding as far as you want the depth of the hole to be. Then leave the block on the bit while the boring is done (See Figure 27), and you will not be required to pay any attention to the depth, simply bore until the block strikes the face of the material.

Figure 27.