Fig. 45 shows a tool which has proved very useful. It is a tool for measuring tapers on dowel pins, reamers, drill shanks, or anything to be tapered. Most machinists know that to find the taper of a shank they must use their calipers for one end and reset them for the other end; or else caliper two places, say, three inches apart, and if, for instance, the difference should be 1/16 inch, they must multiply this difference by four to get the taper per foot. With the tool above mentioned, all this trouble in calipering and figuring is saved. Simply place the shank or reamer to be measured between pins _A_, _B_, _C_, and _D_, and slide _H_ and _K_ together. Then the taper can be read at once on the graduated scale at _L_. The construction of the tool will be readily understood. The body or base _F_ has a cross piece supporting the two pins _A_ and _B_. On this slides piece _K_, which has at its right end the graduated segment. The screw _G_ is fast to piece _K_, and upon it swivels the pointer _E_, which carries the two pins _C_ and _D_. Thus these two pins can be brought into contact with a tapered piece of any diameter within the capacity of the tool, and the swivel screw _G_ allows the pins to adjust themselves to the taper of the work and the pointer _E_ to move to the left or right, showing instantly the taper per foot. As the pins _A_ and _B_ are 1½ inch apart, which is 1/8 of a foot, and the distance from _G_ to _L_ is 4½ inches, which is three times longer than the distance between _A_ and _B_, the graduations should be 3/64 inch apart, in order to indicate the taper per foot in eighths of an inch.[23] Taper Gage [Illustration: Fig. 46. Handy Taper Gage] A handy taper gage is shown in Fig. 46. The blades of the gage are made of tool steel. The edge of the blade _A_ is V-shaped, and the blade _B_ has a V-groove to correspond. The end of _B_ is offset so as to make the joint and allow the two blades to be in the same plane. A strong screw and nut are provided to hold the blades at any setting. The user of this gage looks under the edge of _A_, and is thereby enabled to tell whether the taper coincides with that set by the gage, and also where a taper piece needs touching up to make it true.[24] Test Gage for Maintaining Standard Tapers [Illustration: Fig. 47. Test Gage for Maintaining Standard Tapers]