more space than the regular anvil, the readings of the micrometer cannot be direct. The plunger _B_ can be made of such dimensions, however, that 0.100 inch deducted from the barrel and thimble reading will give the actual dimension. Such a deduction is easily done in all cases. In other words, the reading of the micrometer should be 0.100 when the face of the measuring screw is in contact with the face of the plunger; the 0.100 inch mark is thus the zero line of this measuring tool. When desiring to measure a number of pieces, a standard size piece or gage is placed between the plunger _B_ and the face _L_ of the micrometer screw, and the instrument is adjusted until the indicator points exactly to zero on the small scale provided on the body of the micrometer. After this the micrometer is locked, and the pieces to be measured are pushed one after another between the face _L_ and the plunger _B_, the indications of the pointer _M_ being meanwhile observed. Whenever the pointer shows too great a difference, the piece, of course, does not pass inspection. All deviations are easily detected, and any person of ordinary common sense can be employed for inspecting the work. Micrometer Scale [Illustration: Fig. 44. Micrometer Mounted on Machinist's Scale] A micrometer, mounted as shown in Fig. 44 is very handy. The micrometer may be used in combination with a 4-, 6-, 9-, or 12-inch scale. It can be adjusted on standard plugs, or one can make a set of gages up to 12 inches, out of 3/16-inch round tool steel wire, and use these for setting. In mounting the micrometer, before cutting it apart, mill the shoulders shown at _A_, and in milling the bottom pieces _B_, use a piece of machine steel long enough for both, cutting the piece in half after milling the slots. In this way one obtains perfect alignment. In a shop where a set of large micrometers is not kept, this arrangement is very useful.[22] * * * * * CHAPTER IV MISCELLANEOUS MEASURING TOOLS AND GAGES Among the miscellaneous measuring tools and gages dealt with in this chapter are tools and gages for measuring and comparing tapers, adjustable gages, radius gages, gages for grinding drills, sensitive gages, tools for gaging taper threaded holes, contour gages, etc. Of course, these are offered merely as examples of what can be done in the line of measuring tools for different purposes, and, while having a distinct and direct value to the mechanic, they also have a great indirect value, because they furnish suggestions for the designing and making of tools for similar purposes. Tool for Measuring Tapers [Illustration: Fig. 45. Taper Measuring Tool]