Thomson, Sir William (Baron Kelvin of Largs)
Thomson was the son of James Thomson, who, at the time of his son’s birth, was professor of engineering at Belfast. In 1832 he became professor of mathematics at Glasgow. He was the author of several noted texts on differential and integral calculus, and he educated William and another son, James, at home. In 1834 both boys matriculated at Glasgow, where the environment was one characteristic of the Scottish universities of the time, which differed greatly from Cambridge. Whereas at Cambridge there was no chair in natural philosophy, nor much interest in the work of the Parisian analysts of the first third of the century, at Glasgow there was a professorship in natural philosophy (held by William Meickleham, who was succeeded by Nichol and then by William Thomson); there was also a chair in chemistry (held by Thomas Thomson).
Meickleham had a great interest in the French approach to physical science and much respect for it. In 1904 Thomson recalled how, “My predecessor in the Natural Philosophy Chair … taught his students reverence for the great French mathematicians Legendre, Lagrange, and Laplace. His immediate successor, Dr. Nichol, added Fresnel and Fourier to this list of scientific nobles.”1
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: