[The following note describes a series of notebooks that were not selected. 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 selected notebooks, use the "Which Series Notes?" button to enter the Series Notes.]

These eight notebooks, which cover the period 1911-1920, encompass a variety of experiments by Zachariah P. Halpin, Albert F. Wurth, and other employees. Included are reports on disc original masters and master molds not completed, data on the printing and transferring of experimental records, and information regarding the quality of printed records. One book describes the physical equipment, mold holders, rotators, and tables used for electroplating. Also included are experiments on improving the wax used in disc records, on the heat in the record manufacturing process, on the springs in recorders and phonographs, and on reproducers. One book contains information about repair of phonograph parts, machine tools needed for phonographs, and the care of phonographs and cabinets. Another has entries on cabinet design, along with tests of mechanical parts, such as turntable springs and governors.