Sub-series 4. Notebooks, 1924-1977

Arranged alphabetically by subject, this sub-series contains Arnold O. Beckman's personal notebooks. A large majority of its contents consist of appointment books kept by Beckman between 1948 and 1977, which provide limited documentation of Beckman's daily activities with National Technical Laboratories and Beckman Instruments, Incorporated, and his activities outside of the firm. The information written in the appointment books includes times and dates for appointments, meetings, and travel arrangements.

Also preserved in this sub-series is a notebook/ledger kept by Beckman between 1924 and 1935. Written in this notebook/ledger are a few ideas and designs for instruments that Beckman believed to be patentable, including his "signaling device", which was patented in 1928. A brief correspondence record from 1925 and Beckman's daily notes regarding work on his non-clogging postal meter ink, inking appliances, and pH meter are also entered in this notebook/ledger. Financial information regarding Beckman's consultant work (including work he performed for National Postal Meter Company), and Christmas card lists are written in the notebook/ledger as well.