On looking again into the matter, the juxtaposition of all the circumstances induced in my mind a strong suspicion that Mrs. C. Barton was _privately married_ to Lord Halifax, probably before his elevation to the peerage, and that the marriage was no very great secret among their friends. As yet I can but say that the hypothesis of a private marriage is, to me, the most probable of those among which a choice must be made: farther information may be obtained by publication of the case in "N. & Q.," the most appropriate place of deposit for the provisional result of unfinished inquiries. Charles Montague (born April, 1661, died May 19, 1715) made acquaintance with Newton when both were at Trinity College in 1680 and 1681. Newton was nineteen years older than Montague, and had been twelve years Lucasian professor. At the beginning of their friendship, the Lucasian professor must be called the patron of the young undergraduate, who was looking for a fellowship with the intention of taking orders, a design which he did not find sufficient encouragement to abandon until after he had sat in the Convention. By 1690, the rising politician had become the patron of the author of the _Principia_, who in that {430} year or the next became an aspirant for public employment. The friendship of Newton and Montague lasted until the death of the latter, interrupted only by a coolness (on Newton's side at least) in 1691, arising out of a suspicion in Newton's mind that Montague was not sincere in his intentions towards his friend. Catherine Barton (born 1680, died 1739) was the daughter of Robert Barton and Newton's half-sister, Hannah Smith (Baily's _Flamsteed, Supplement_, p. 750.). Lieut.-Col. Barton, usually called her husband, was her brother. The pedigrees published by Turnor recognise this fact: Swift distinctly states it, and Rigaud proves it in various ways in letters to Baily, which lately passed through my hands on their way to the Observatory at Greenwich. The mistake ought never to have been made, for _Mrs. C. Barton_ (as she was usually denominated) must, according to usage, have been reputed single so long as her Christian name was introduced.