_USNM 604398 (S-K 545). Figure 91._
[Illustration: FIGURE 91]
This specimen is identical to the preceding plate except that it is
fitted with two brass hooks for attachment to the belt and the reverse
is stamped with the maker's name, "Boyd & Sons." No trace of a
manufacturer of such products by the name of Boyd has been found. It
is probable that he worked during the Civil War period when there were
many such contractors.