[This note covers all of the notebooks in Group 10: Nickel-Cobalt Ore Assay Notebooks.]

These twelve undated notebooks were probably used during the period 1905-1907. The books primarily contain the results of assays made by unidentified employees to determine the presence of nickel and cobalt in ore samples. Within each book the entries are consecutively numbered, generally beginning with number one. N-06-00-00.1 begins with number 1254 and is a continuation of N-05-11-09. In addition to the assays, there are a few experimental notes by Edison regarding the processing of these ores, along with a few entries noting the locations of mines. Also included are requests for samples, notes about samples received at the laboratory, and notes about the availability of ores. In several of the books the initial entries in the assay log are by Edison, while subsequent entries are by other experimenters. In such books only the Edison material has been selected, although the unselected pages do contain occasional notations by Edison regarding the assay process or results.