Specification of John Aspinall : apparatus for obtaining extracts and decoctions
A British patent specification by John Aspinall, published in London by the Great Seal Patent Office in 1856, describing apparatus for making plant extracts and decoctions such as coffee and dye liquors. The one picture is not an engraving of the apparatus but the royal arms crest, a crowned shield flanked by a lion and a unicorn on a scrolled banner, which marks the official seal of the patent office and offers a designer a heraldic emblem to borrow.
