Logan, James

Logan, James

(b. Lurgan, Ireland, 20 October 1674;d. Germantown, Pennsylvania, 31 October 1751)

dissemination of knowledge.

The most intellectually capable scientist of colonial America, Logan published works in botany and optics. His major contribution, however, lay in his acknowledged competence in science and in the help and advice that he gave to Thomas Godfrey, John Bartram, Benjamin Franklin, and Cadwallader Colden.

Logan was the son of Patrick Logan, a Scotch Quaker schoolmaster who moved in 1690 from Lurgan to Bristol, where he taught school assisted by his son. James Logan learned Latin and Greek as well as a number of other languages, including Arabic and Italian, He taught himself mathematics by mastering William Leybourn’s Cursus mathematicus, only one work in his boasted first library of 700 volumes, which he later sold in order to invest in the linen trade. Having failed to so establish himself, in 1699 Logan accepted William Penn’s invitation to accompany him to Pennsylvania as his secretary.

On his return to England in 1701, Penn left the twenty-seven-year-old Logan in charge of his affairs. For over four decades—as administrator, land agent, and merchant—he represented, not without dispute, the interests of Penn and his heirs. He was first secretary to and then for most of his life a member of the provincial council, mayor of Philadelphia in 1722-1723, chief justice of the Supreme Court of Pennsylvania in 1731-1739, and acting governor of the colony in 1736-1737. He negotiated treaties with the Indians and foresaw a clash with the French on the frontiers. He designed the Conestoga wagon to transport trade goods to Indian country and furs for export back to Philadelphia. He became rich through personal investments in land and an active mercantile trade.

Logan’s copy of the Principia, which he bought in 1708 while he was in London, was the first known in America, On the same trip Logan saw Newton perform an experiment on the velocity of falling bodies under the dome of St. Paul’s. He also made the acquaintance of a number of learned English men, including Flamsteed, and haunted the bookshops of London. Self-taught from books—which he bought in increasing quantities as he grew older and richer—Logan became highly knowledgeable in mathematics, natural history, and astronomy, making observations with his own telescope. Unhappily alone on the frontier of civilization without intellectual peers to converse with, he entered into extensive correspondence with Robert Hunter and William Burnet, successive governors of New York; the Quaker scholar Josiah Martin; Johann Albrecht Fabricius; William Jones, the British mathematician; John Fothergill, the Quaker physician; and Peter Collinson.

On his second trip to England in 1723-1724, Logan procured a set of sheets of Edmond Halley’s still unpublished moon tables and added to them an explanation of Halley’s method and an account of his own observation of the solar eclipse of 11 May 1724, which he watched at Windsor with members of the Penn family. Many of his astronomical books, some of which he procured from the widow of Johann Jacob Zimmerman, the German scientist and pietism, are full of notes, corrections, and comments, including Flamsteed’s suppressed calculations of stars which Logan inserted in his own copy of Hevelius’ Prodromus Astronomiae.

Thomas Godfrey, a glazier, was introduced to higher mathematics by Logan and became so proficient that he invented an improved mariner’s quadrant. In 1732 Logan vigorously defended Godfrey’s claim to the invention before the Royal Society against the simultaneous announcement of a similar instrument by John Hadley. His letters on behalf of Godfrey were supplemented by his own communications to the Royal Society, including in 1735 a preliminary essay on the generation of Indian corn, and in 1736 observations on a Hebrew shekel (which he sent as a gift), further notes on his corn experiments, a theory to explain the crooked aspect of lightning, and a hypothesis to account for the huge appearance of the moon on the horizon. He was, however, never made a fellow of the Royal Society.

In 1727 Logan read of the theories of seminal preformation and aerial pollination and began his own experiments with Indian corn. After his initial letter to the Royal Society, he worked to improve his techniques and to make his conclusions more explicit. Although the British scientists took little notice of his work, it was received enthusiastically on the Continent. Linnaeus hailed Logan as one of the heroes of botany, and Johann Friedrich Gronovius saw that the essay was published in full at Leiden in 1739 as Experimenta et meletemata de plantarum. Others had noted the sexuality of plants and pollination; Logan, by covering the flowers of corn with linen bags and by cutting off the tassels, demonstrated how the pollen generates kernels, or seeds, by ascending the tassels. Fothergill translated the work into English as Experiments and Considerations on the Generation of Plants, and it was published in London in 1747, Logan’s work, a pioneer step toward plant hybridization, was referred to throughout the century. Within a year of the publication of Linnaeus’ Systema naturae in 1735 Logan had acquired a copy. He introduced the “natural” naturalist, John Bartram, to the advances in taxonomy and taught him enough Latin to be able to read Linnaeus. It was through his encouragement and introductions that Bartram became known to botanists abroad.

Logan’s scientific virtuosity found other expression. His simplification of Christiaan Huygens’ method of finding the refraction of a lens appeared at the end of his Experimenta as “Canonum pro inveniendis refractionum.” A second work in optics was even bolder. Starting with Huygens and going beyond Newton, he tried to show that the laws of spherical aberration could be more briefly expressed mathematically otherwise than geometrically. His treatise Demonstrationes de radiorum lucis in superficies sphaericas was reprinted at Leiden in 1741 with the help of Gronovius, whose colleague Pieter van Musschenbroek read the proofs. Such was Logan’s at home that Franklin brought him the accounts of his experiments in electricity to read before he sent them off to England.

Early in 1728 Logan slipped on ice and broke the head of his thighbone; it never healed, and he was lame for the rest his life. In 1730, after moving to his country house, Stenton, in Germantown, he tried with only moderate success to free himself of administrative responsibilities so that he could devote himself to his books. His translation of the pseudo-Cato’s Moral Distichs was printed by Franklin in 1735, and his more famous version of Cicero’s Cato major, written in 1733, was issued in 1744, also from Franklin’s press. These, as well as his scientific articles, were minor works. During the second half of the 1730’s Logan worked in bursts of energy upon a major philosophical treatise, “The Duties of Man Deduced from Nature.” The recently rediscovered manuscript contains three completed chapters, one almost complete, and two only begun. In the section “Of the Exterior Senses” Logan brought to bear his knowledge of mathematics, harmonics, and medicine. The work, although imperfect, is the only surviving nontheological tractate on moral philosophy written in colonial America.

In 1742 Logan decided to bequeath his extensive library for public use and to spend his remaining years increasing it. By a codicil to his will, canceled because of a disagreement with his son-in-law, Isaac Norris, who had been named one of the trustees, he had left his books to be installed in a building at Sixth and Walnut Streets in Philadelphia. After his death his children established the Bibliotheca Loganiana, then consisting of about 2,600 volumes, as a trust in accordance with their father’s unfulfilled intentions. In 1792 the trust was transferred to the Library Company of Philadelphia, where the books have remained ever since. The finest library in British America, it is now the only collection of its kind that has been preserved virtually intact. As he wrote for Franklin in 1749, Logan’s library contained “A good Collection of Mathematical Pieces, as Newton in all three Editions, Wallis, Huygens, Tacquet, Deschales, &c. in near 100 Vols, in all Sizes.” He had in addition all the works of the ancient mathematicians, a large collection of astronomical works, and as good a representation of books on natural history as could be found in the colonies. His impact as a scientist was limited, for, with few exceptions, he read, worked, and experimented for his own intellectual enjoyment.

BIBLIOGRAPHY

I. Original Works. Logan’s writings have been mentioned in the text; he also published a number of political pamphlets and broadsides. His philosophical treatise, “The Duties of Man Deduced From Nature,” in the Historical Society of Pennsylvania, is still unpublished. The principal materials on Logan’s life are in the extensive Logan Papers in the Historical Society of Pennsylvania, which include MSS of many of his writings, a virtually complete run of letter books and other documents by and about him, but no corpus of letters received.

II. Secondary Literature. The only adequate biography of Logan is Frederick B. Tolles, James Logan and the Culture of Provincial America (Boston, 1957) but it is too brief. Logan’s experiments on Indian corn are treated by Conway Zirkle, The Beginnings of Plant Hybridization and Sex in Plants (Philadelphia, 1935). His mathematical knowledge is noted, somewhat inaccurately, by Frederick E. Brasch, “James Logan, a Colonial Mathematical Scholar, and the First Copy of Newton’s Principia to Arrive in the Colonies,” in Proceedings of the American Philosophical Society, 86 (1942), 3-12. The best general appraisal of Logan as a scientist is Frederick B. Tolles, “Philadelphia’s First Scientist, James Logan,” in Isis, 47 (1956), 2-30. The Catalogus bibliothecae Loganianae (Philadelphia, 1760) lists his library as it existed at the time of his death. A detailed catalogue of that library, noting his extensive annotations and his correspondence about the books, is being compiled by the author.

Edwin Wolf II