[Illustration: _Extract from The Pennsylvania Mercury of 7 April 1775. Courtesy of the Harvard College Library._]
Rejoicing in their encouragement of native manufactures, the practical support they were giving to the Pennsylvania non-importation resolutions of six months earlier, the publishers of the _Mercury_ advertised on 23 June 1775 _The Impenetrable Secret_ as a work "Just Published and Printed with Types, Paper and Ink, Manufactured in this Province." If they had added, as possibly they might have done with truth, "on a press of Philadelphia make," we could regard this statement as the declaration of independence of the American printer from the English manufacturer.[15]
Isaiah Thomas says that the _Pennsylvania Mercury_ was established with the backing of Joseph Galloway as a substitute for the _Pennsylvania Chronicle_, that disastrous earlier venture in journalism in which the Quaker politician had engaged with William Goddard. If this was the case, certain features of the new publication must have been displeasing to the silent partner, for Galloway the Tory could hardly have rejoiced with the publishers in their virtuous encouragement of native type founding, with all its patriotic implications. Furthermore, from an advertisement of John Willis and Henry Vogt in the first issue of the paper one learns that the publishers were making use of other articles of printing equipment made by these general craftsmen, who here announced their ability to make presses and any and all of the mechanical appurtenances required in a printing shop. This well-advertised Americanism of the publishers, however, seems not to have availed them in the attainment of success, and after their establishment had been destroyed by fire in the closing days of the year the business was never resumed.
It is not certainly known who was the maker of the significant _Mercury_ types. Assuming that Sower's foundry was in full operation in the early months of 1775, we must assume also, in the absence of knowledge to the contrary, that its principal activity was in the manufacture of German letters for the great Bible, first published in 1776, and that Sower would not have been likely to engage in the making of Roman type on a large scale until this work had been completed. Because of our ignorance of other possibilities there remain to be considered only the two craftsmen, Fox and Bay, as the probable makers of this first successful American letter. According to McCulloch, Fox had cut and cast Roman letter at some period before the year 1774 while still working for Sower. This statement contains all that is known of his efforts at making Roman type during the years that he remained with Sower, but there is the chance to be taken into account that the _Mercury_ font was the result of his experimentation during this period in an art which later he pursued with no small degree of local success. On the same authority it is said, it will be remembered, that Jacob Bay had left Sower in 1774, and in a near-by house in Germantown had set up a type foundry on his own account. In this separate establishment, it is likely that he was able to devote to the business such time and energy as would be required in making a font of sufficient size to accommodate the needs of such a newspaper as the _Pennsylvania Mercury_. The fact of his separate foundry having been established sometime in 1774, the reference in the Convention resolution of January 1775 to the "ingenious artist" at Germantown and the appearance in April 1775 of the new font of type acclaimed by the publishers as "an attempt to introduce so valuable an art into these colonies" are considerations which, taken in their order, seem to give ground for an assumption that it was Jacob Bay who cut and cast the letters for "The first Work with Amer. Types." Until proof is forthcoming, however, this must remain an assumption and nothing more.