 I. B. Cohen (1985, chap. 2) lays down four historical tests, four necessary conditions, for the correct attribution of a revolution. First, the scientists involved in the development must perceive themselves as revolutionaries, and relevant contemporaries must agree that a revolution is underway. Second, documentary histories must count it as a revolution. Third, later historians and philosophers must agree with this attribution and, fourth, so must later scientists working in that field or its successors. By including both reports from the time of the alleged revolution and later historiographical judgments, Cohen excludes people who claimed in their day to be revolutionaries but who had insufficient impact on the field to sustain the judgment of history. He also guards against whiggish, post hoc attributions of revolution to people who had no idea that they were revolutionaries. His own four examples of big scientific revolutions all have an institutional dimension: The Scientific Revolution featured the rise of scientific societies and journals, the second was the aforementioned revolution in measurement from roughly 1800 to 1850 (which Kuhn, too, called “the second scientific revolution”; 1977, 220). Third is the rise of university graduate research toward the end of that century. Fourth is the post-World War II explosion in government funding of science and its institutions. 