At head of title: Library of Congress., "Printed as manuscript.", "The ... classification is in its general design and in many details the work of Mr. Martel. To Miss Mary W. MacNair the scheme owes its ... index; and the construction of the scheme throughout has been under the supervision of the chief classifier, Mr. Perley."--Preface (signed: Alfred F.W. Schmidt, classifier in charge)., and AVAILABLE ONLINE TO AUTHORIZED PSU USERS AS PART OF LLMC-DIGITAL.