The son of John Hooke, a minister, Hooke was a sickly boy; although he ultimately lived to be nearly seventy, his parents did not entertain serious hope for his very survival during the first few years of his life. His father, one of three or four brothers, all of whom found their calling in the church, intended young Robert for the ministry also; but when persistent headaches interrupted the intended program of study, his father abandoned the plan and left the boy to his own devices. What these would be was immediately manifest. When he saw a clock being dismantled, he promptly made a working replica from wood. He constructed ingenious mechanical toys, including a model of a fully rigged man-of-war which could both sail and fire a salvo. By his tenth birthday Hooke had already embraced what his biographer Richard Waller called “his first and last Mistress”—mechanics. His role in the history of science is inextricably bound to his skill in mechanics and his allied perception of nature as a great machine.
When his father died in 1648, Hooke inherited £100. Since he had displayed some artistic talent, his family packed him off to London, where his legacy was to finance an apprenticeship to Sir Peter Lely. Hooke decided to save his money; and it was his good fortune that Richard Busby, the master of Westminster School, befriended him and took him into his home. The teacher had recognized the pupil. Not only did Hooke learn Latin, the staple of the secondary curriculum, together with Greek and a smattering of Hebrew; he also discovered mathematics. By his own account he devoured the first six books of Euclid in a week, and he proceeded to apply geometry to mechanics. Nor was mathematics all. By his own account again, he learned to play twenty lessons on the organ and invented thirty ways of flying. Having exhausted the resources of Westminster, he moved on to Oxford, where he entered Christ Church as a chorister in 1653.
Figures & Tables
In this chapter, we give a brief synopsis of each of the classic papers referred to in this collection. Where relevant, we reproduce the basic equations, recast in modern notation. Supporting works also are referred to. They are listed in the “General References” section.
Table 1 is a quick outline of the key contributions of each paper reprinted in this book.
Robert Hooke, “Potentia Restitutiva, or Spring” (Oxford, 1678)
The article by Robert Hooke, “Potentia Restitutiva, or Spring,” contains the statement of the proportional relation between stress and strain universally referred to as Hooke’s law. Although the English language has evolved somewhat since 1678, the article does not require translation. Hooke describes a variety of experiments, accompanied by illustrations, confirming the stress/strain relation over a wide range of applied loads. He emphasizes the great generality of his results.
Based on his experimental work from 1660 onward, Hooke first published his law in 1676 in the form of an anagram in Latin,
which he later revealed to be “ut tensio sic vis.” Roughly translated, this means “as the force, so is the displacement” (Love, 1911; Boyce and DiPrima, 1976).
In his treatise, Hooke examined the behavior of springs, so his first casting of the equations dealt with the restoring force on a spring, for a given displacement: