Care has been taken to make all statements accurate and clear, with the purpose of bringing essential information within the understanding of beginners in the different fields of study.

Wherever practicable, simple and well-defined drawings and illustrations have been used to assist in giving additional clearness to the text.
In order that the pamphlets may be of the greatest possible help for use in trade-school classes and for self-instruction, each title is accompanied by a list of Review Questions covering essential items of the subject matter.
A short Glossary of technical terms belonging to the subject or department treated is also added to many of the books.
These are the Official Text-books of the United Typothetae of America.
Address all orders and inquiries to COMMITTEE ON EDUCATION, UNITED TYPOTHETAE OF AMERICA, CHICAGO, ILLINOIS, U.S.A..