| |
|Large diameter and |Diameter at small |Divide taper per foot by |
| length of taper in | end in inches. | 12; multiply by length |
| inches and taper | | of length of taper, and |
| per foot. | | subtract result from |
| | | large diameter. |
| | | |
|Small diameter and |Diameter at large |Divide taper per foot by |
| length of taper in | end in inches. | 12; multiply by length |
| inches, and taper | | of taper, and add result|
| per foot. | | to small diameter. |
| | | |
|The taper per foot |Distance between | Subtract small diameter |
| and two diameters | two given diameters| from large; divide re- |
| in inches. | in inches. | mainder by taper per |
| | | foot, and multiply |
| | | quotient by 12. |
| | | |
|The taper per foot. |Amount of taper in | Divide taper per foot by |
| | a certain length | 12; multiply by given |
| | given in inches. | length of tapered part.|
+---------------------+---------------------+--------------------------+

=Accurate Measurement of Angles and Tapers.=--When great accuracy is
required in the measurement of angles, or when originating tapers,
disks are commonly used. The principle of the disk method of taper
measurement is that if two disks of unequal diameters are placed either
in contact or a certain distance apart, lines tangent to their
peripheries will represent an angle or taper, the degree of which
depends upon the diameters of the two disks and the distance between
them. The gage shown in Fig. 16, which is a form commonly used for
originating tapers or measuring angles accurately, is set by means of
disks. This gage consists of two adjustable straight-edges _A_ and
_A_{1}_, which are in contact with disks _B_ and _B_{1}_. The angle
[alpha] or the taper between the straight-edges depends, of course, upon
the diameters of the disks and the center distance _C_, and as these
three