. Digest of agricultural implements, patented in the United States from A.D. 1789 to July 1881 ... Agricultural machinery; Patents. ^:&quot;^,^. ..^ 'v^ '^X''*^&quot;^^^''**^ -^-^i ), 1 G, ARMSTRONG. Improvement in Gang-Plows. JP^^. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original work.. Allen, James T. (James Titus); United States. Patent Office. [New York, Printed by J. C. Von Arx - Stock Image