Eli Whitney Blake was a member of a leading family of industrialists in New Haven, Connecticut, which had a tradition of invention and entrepreneurship. The family’s main business was the manufacture of arms, but family members participated in civic affairs and assisted in planning the development and servicing of the city. Genetics may have been a factor in Blake’s inventiveness—his mother was the sister of Eli Whitney, who invented the roller cotton gin.
In 1852, the town council decided to pave Whalley Street, a 2-mile-long thoroughfare in the central part of the city. Blake was one of the townsmen responsible for planning the paving project, which employed the MacAdam system—in use for road building since 1815. In this system, the surface of a road was formed by interlocking stones that had passed through 2-in. apertures and then sealed. The practice of the day was to break rocks by hand, which was slow and costly. Realizing that a machine could break quarried rock faster and cheaper than a man, Blake designed the first efficient jaw crusher (Dickinson 1945). This invention was remarkable; he used converging fixed and moving jaws and drove the moving jaw through a toggle joint that exerted immense pressure on the jaw when its members were moved into a straight line. The design, which was prepared before the first machine was built, has changed little in its essentials for 150 years. Jaw crushers built to Blake’s design are still widely used today.