Hand-tools have a long history. Evidence of hammer-stones and hand axes date from about 2.6 million years ago. That’s well over 2 million years before the appearance of Homo sapiens about 200,000 years ago. Nearly all of those millennia passed before the development of the monkey wrench. On this date in 1835, the adjustable or screw wrench was patented by Solymon Merrick of Springfield, Massachusetts. The modern looking wrench was soon followed by improved designs that are still in use today. There are 900 establishments in the U.S. making the hand and edge tools that are the descendants of the prehistoric hammer stones and hand axes. The $5-billion a year industry employs some 23,000 people. You can find more facts about America from the U.S. Census Bureau online at <www.census.gov>.