Though Charles never became active in politics, he was an advocate of proportional representation. Zina made notes of his conversations with her about it, and published his views in two of her later books.
Though Zina was not a scientist, she did become a member of the international scientific community by serving, like Charles, as an observer near Catania in Sicily of the total eclipse of the sun on 22 December 1870 and by the inclusion of her excellent account of it in the annual report of the Coast Survey for that year.
Zina’s younger sister Amy Fay was a gifted pianist who, after the best training that could be had in New England, studied in Germany from 1869 to 1875 under several of its best teachers, including Tausig, Kullak, and Deppe in Berlin and Liszt in Weimar. By visiting her in Germany and by reading her long and frequent letters home, Zina and Charles became vicarious members of the international community of musicians. Zina published selections from the letters in the Atlantic Monthly for April and October 1874, and later a more comprehensive collection in book form, in a single chronological order, under the title Music-Study in Germany. It went through more than twenty editions, was translated into French and German, and is still in print. The first twelve chapters come within the period of the present volume. One of them contains a vivid account of the five days that Amy and Charles spent in Dresden in August 1870.
Within the period of the present volume Peirce became acquainted with modern German experimental psychology, as represented by Weber, Fechner, Wundt, and Helmholtz. By 1869 he was already contemplating experiments of the kind he carried out with Jastrow in 1884, which made him the first modern experimental psychologist on the American continent. He sent Wundt copies of his Journal of Speculative Philosophy papers and asked permission to translate Wundt’s Vorlesungen über die Menschen- und Thierseele, to which he refers in appreciative terms on page 307 below. Wundt’s reply thanking him for the papers and granting the permission was dated at Heidelberg 2 May 1869. No translation by Peirce was published, and no drafts have been found. A translation of the much revised edition of 1892 was published by J. E. Creighton and E. B. Titchener in 1894 and reviewed by Peirce in the Nation. When Helmholtz visited New York City in 1893, Peirce had a visit with him, and his long obituary of Helmholtz in 1894 was reprinted in Pollak’s 1915 anthology of the Nation’s first fifty years.
Back now to logic. In his Harvard University Lectures on the logic of science in the spring of 1865, a few months after the death of George Boole, Peirce had said that Boole’s 1854 Investigation of the Laws of Thought “is destined to mark a great epoch in logic; for it contains a conception which in point of fruitfulness will rival that of Aristotle’s Organon” (WI:224). In the first of his fifteen Harvard University Lectures of 1869–70 on “British Logicians,” before turning to medieval nominalism and realism, Peirce said, according to the notes of one of his students, that there was enough in Boole to “take the whole time” of the course. By 1877 the British mathematician and philosopher W. K. Clifford was ready to say that “Charles Peirce … is the greatest living logician, and the second man since Aristotle who has added to the subject something material, the other man being George Boole, author of The Laws of Thought.”10
What was the “something material” that Peirce had added? That takes us back once more to 1867, for it certainly included “On an Improvement in Boole’s Calculus of Logic.” What else? At the very least, and above everything else, the most difficult and, at least for logicians and for historians of logic, the most important paper in the present volume: “Description of a Notation for the Logic of Relatives, resulting from an Amplification of the Conceptions of Boole’s Calculus of Logic” (DNLR).11 But is it not the case that, though the logic of relations can be traced back at least to Aristotle, De Morgan was the first logician to invent a notation for it? And was not that in 1860, a decade before Peirce’s memoir? Yes, but as soon as Peirce’s memoir began to circulate, there was room for the question whether De Morgan’s notation might be a dead end. In his obituary of De Morgan, Peirce said (p. 450 below) “it may at least be confidently predicted that the logic of relatives, which he was the first to investigate extensively, will eventually be recognized as a part of logic.” He did not predict, however, that it would be in De Morgan’s notation that it would achieve that recognition. But was not the Boole-Peirce-Schroder line in logic superseded by the Frege-Peano-Russell-Whitehead line? No; it was only eclipsed.
Even more intimately than with Boole and De Morgan, Peirce associated his DNLR with his father’s Linear Associative Algebra. The two appeared at almost the same time, midway between two total eclipses of the sun, but the connections between them did not become fully apparent until, after his father’s death in 1880, Peirce prepared a second edition of the LAA, with an addendum by his father and two addenda by himself, and with well over a hundred footnotes to the original text, in over sixty of which he supplied translations from the LAA formulas into DNLR formulas.
Peirce’s father had been one of the founding members of the National Academy of Sciences in 1863. Beginning in 1867, he presented instalments of the LAA at meetings of the Academy.12 Charles’s focus on the logic of relations went back to his earliest work on his categories. A logician who had only three central categories —Quality, Relation, and Representation—was bound to return again and again to the logic of relations. Recall, for example, his remarks about equiparant and disquiparant relations in volume 1, and note what he says about mathematical syllogisms on 42 f. below. But his earliest published mention of De Morgan’s paper of 1860 was written late in 1868 (p. 245n2), and he may not have seen that paper more than a few weeks earlier. So the actual composing of the DNLR may have begun in 1869.
Then, on 7 August 1869, came the first of the two eclipses. It was observed by several teams at several points along the line of totality. Peirce and Shaler were stationed at Bardstown, Kentucky. Their report, one of the most vivid as well as detailed, was submitted by Peirce to Winlock, included in Winlock’s report to Superintendent Peirce, and published by him in the Survey’s Annual Report. It reappears on pages 290–93 below. A quarter of a century later, in an unpublished paper entitled “Argon, Helium, and Helium’s Partner,” Peirce gave an equally vivid retrospective account (Robin MS 1036).
I remember, as if it were yesterday, the first time I saw helium. It was in 1869. Astronomical spectroscopy was then in its earliest infancy. … It was impossible in those early days, for the same observer to point his telescope and to use the spectroscope; so I had brought along with me the Kentuckian geologist Shaler, a man of nerve and proved in war, to bring successively the different protuberances of the sun upon the slit of my spectroscope, while I examined the spectrum and recognized what I could.…
The observations of the sun’s corona and protuberances by the Peirce-Shaler and other teams prompted new theories as to the composition of the sun, but there was some skepticism about these theories among European astronomers. The earliest opportunity for a test of them would be the eclipse of 22 December 1870, whose path of totality was to pass through the Mediterranean. It was desirable that as many as possible of the American observers of the 1869 eclipse should be observers of the 1870 one also, and Peirce’s father began making plans to bring that about. One of these plans was to have Charles follow the path of totality from east to west several months in advance, inspecting possible