Memorial to an Unknown Printer

I've been reading the library lately. Specifically, the outside walls of the big one downtown, which are covered with quotes by philosophers Milton and Carlyle and Carnegie, the 19th Century robber baron who donated money to start the public library system in St. Louis. The outside walls also pay tribute to early printers, dating from the 13th to 18th Centuries. Among those so honored is an "Unknown" printer from St. Albans whose contribution is noted as being from 1480, more than a decade before North America was discovered by Columbus.