During the decades immediately after its discovery, the Boyle-Mariotte gas law was formulated in terms of pneumatic “springs,” subsumed by Hooke under his own stress-strain relation, and generally regarded as a law of elasticity. The subsequent historical development of Boyle's principle, and that of the concept of elasticity with which it is no longer associated, provide thought-provoking test cases for Thomas Kuhn's notions of paradigm and puzzle solving in physics.