It is certain that both Fox and Bay maintained their interest in letter casting for many years. At the sale of Sower's confiscated property in the year 1778 both of these artisans were present as purchasers of type-making tools and material.[16] Bay especially seems to have taken advantage of the opportunity to secure equipment at this dispersal of his old master's goods. Among other purchases which he made at the sale of what was probably at the time the largest typographical establishment in the country were "a lot of letter moles" at three pounds, "a Box with 9 Crusibles" at £5 15_s._, a quantity of worn type at 8_d._ a pound and antimony worth £8 18_s._ 3_d._ He was living at the time in a house rented from Sower,[17] and at the sale of the printer's real property in September 1779 he purchased another house belonging to the estate for £4200, a sum which he paid in two installments before 28 October 1779.[18] In recording from tradition the fact that Bay secured at this time one of the Sower houses, McCulloch asserts that he purchased it from John Dunlap, the printer, whom he paid in type of his own making. It is possible that he borrowed the purchase price from Dunlap on this or a similar basis of repayment, a transaction that would explain McCulloch's version of the story. It is said that he conducted his foundry until the year 1789, and that between this year and 1792 he sold the business to Francis Bailey. Fox continued the making of type until his death in the year 1805, when his son and partner Emmanuel Fox sold the equipment to Samuel Sower of Baltimore, the son of Christopher Sower, the Second, of Germantown, whose enterprise had been the determining cause of its existence.
McCulloch was emphatic in his praise of the sturdiness of Fox's types, but when he remarked to Archibald Binny upon the excellent wearing quality of a set of figures and capitals cast by the Germantown founder, which he and his father before him had been using for many years, that gentleman replied with scorn that they were "at first so devilish ugly ... the longest using cannot mar their deformity."
The type-founding operations of Fox and of Bay have greater importance in the history of the art in America than is usually conceded them. When they are referred to at all by general writers, their activities are mentioned briefly or in such a manner as to give one the impression that their efforts were sporadic or tentative. It is with the work of the Scotch founder Baine, using imported equipment, that the story of American type founding is usually begun, but with the _Mercury_ font before us, cut and cast thirteen years before Baine's first operations, and with assurances by McCulloch that Fox cut and cast the letters used in the McKean edition of the _Acts of the Pennsylvania Assembly_, printed by Francis Bailey in 1782,[19] and with references by McCulloch to fonts produced by Bay, it seems certain that there exists material which will require a revision of the story of American type-founding origins. Beginning with the incontestable fact of the successful _Mercury_ font of 1775 and accepting McCulloch's relation of later events as a working hypothesis, there is seen to exist a field for research which should prove productive of discoveries, inasmuch as the fact and the tradition indicate a continuous activity on the part of one or the other of these early Pennsylvania founders, Fox and Bay, from 1775 to 1805. In the course of these years other founders, better known to us, began their work, and between the years 1796 and 1801, more than one hundred American printers, from Massachusetts to Georgia, purchased type from the foundry of Binny & Ronaldson of Philadelphia.[20]