Copy specification of Cawood patent - Cawood, Joseph D. (s.n, 1856)
OCLC, 18832422. - Patent application letter for improvements to the common anvil, or swage block; letters-patent no. 15,687 granted to Cawood, Sept. 9, 1856. - Reproduction of original from Harvard Law School Library. - Signed: Joseph D. Cawood. - Title from caption