The United States Horological Trademark Index is a complete list of all trademarks on watches and clocks registered with the United States Patent and Trademark Office between January 1870 and December 1960. The references include over 4000 illustrations as well as information detailing either filing or issue date, use since date, and type of product claim. Each individual company is alphabetically listed and subsequently each trademark illustrated with a copy of the original mark claimed. If there is more than one mark under a specific company they are then listed chronologically. The book is fully indexed by either text or image and also includes examples of vintage watch and clock advertisments throughout.