Scope and Contents The documents in this collection focus on the material surrounding the creation of the Hamilton Space Clock. This includes sketches and drawings, however the bulk of the material focuses on the press and publicity around the release of the clock. In particular, there are a number of speeches and lectures given by the Hamilton employee who constructed the clock, Ralph Mentzer.Additionally, there are some photographs of the clock, Mentzer, and the inventor of the clock, Dr. I.M....

Scope and Contents This collection is comprised primarily of invoices from the Horolovar Company. Additionally, there are several flyers on the Flying Pendulum Clock and the 400-Day Clock, including a history of the 400-Day Clock.

Scope and Contents This collection is comprised primarily of invoices and bills sent to the Mather Brothers through the years of 1901-1914. This includes bills and invoices from watch and clock companies, watch case companies, and others.