3 Table showing the number of patents, reissues, designs, and additional improvements granted at the Patent Office in Washington during each month of the year 1851. Table showing the number of patents issued to citizens of different States during the year 1851. Patents, reissues, designs and additional improvements are all included in this table, IV. CLASSIFIED LIST OF PATENTS THAT HAVE EXPIRED IN THE YEAR 1851. CLASS I.-Agriculture, including instruments and operations. CLASS II.-Metallurgy and manufacture of metals. IV.—Classified list of patents, &c.—Continued. CLASS III.-Manufactures of fibrous and textile substances, including machines for preparing fibres of wool, cotton, silk, fur, paper, &c. |