[The following note describes a series of notebooks and has no document records attached to it. For that reason, a "no Documents found" message will appear if the "List Documents" button at the bottom of the note is used. To see the records in the notebooks described here, use the "Which Series Notes?" button to enter the Series Notes or use the "Next Text" button to move to the first item in the series.]
These two notebooks were used by George E. Hart during 1920-1921 for notes on experiments with primary and storage batteries and disc records. One notebook with indications of oversight and involvement by Edison has been selected.