The upper cover of the dust jacket juxtaposes the printed page with vaccuum tubes, then a state of the art symbol for electronics. I find the contrast in subject matter of the offerings from the University of Illinois Press advertised on the back cover of the dust jacket interesting: Shannon & Weaver, Hartree on Calculating Machines, and a book on Fifteenth Century Printed books. Published in 1951 before any electronic computers were available, this work emphasized analog methods for information retrieval.