"It was in the service of
Jonathan Marshall that the progenitor of the great firm of
Thomas Firth and Sons acquired that practical skill as a
steel converter which he handed down to his son, and which
was the chief cause of the first success of the firm.
His son besides being with Mr.
Marshall was, before he started in business for himself,
with the Sandersons."
of old Sheffield: Its Streets and Its People
by Robert Eadon Leader, 1876