The Roller-skate

One of the byproducts of Ben's invention of the pulley was his obsession with wheels. In a manner of speaking, Ben Franklin reinvented the wheel - literally - in 1731 with the invention of the roller-skate. The original roller-skate was much less versatile and much more dangerous than the modern variety, but the basic principles were the same. Ben affixed two axles to the soles of standard buckled shoes and installed wheels he removed from a toy carriage. The wheels were reinforced with copper for increased durability (John Adams tells an amusing story of Ben Franklin demonstrating his original prototype only to have the wheels break off under his cumbersome mass). Over the years, Ben only made a handful of pairs, mostly as gifts for the children of his friends. But roller-skating in the 1730s was nothing like it is today; it essentially consisted of rolling downhill.