"622
In 1909, Edison began experimental notebook devoted recording experiments
on solvents used dissolve shellac and like substances.
623 Notebook N-09-04-20 "Solvents" April 20, 1909. This table has two unrelated experimental tasks
occurring the same time and the same table—relatively common Edison’s
laboratory. asked Laverty find out why this residue did not plate. They mark the first efforts
to find materials for records, which dated from the late nineteenth century.621
621 Historian’s Notes 68, 90, and contain recollections Paul Laverty.
The wax and shellac materials used cylinders were early attempts find a
recording medium which was easy mold and difficult break. One his options was shellac, and experimented make soft
enough mould into records and then hard enough preserve the spiral groove
of sound waves, "of such hardness and toughness that approaches celluloid.623 Laverty had the
task testing various solvents used alter shellac.1.625
One interesting experiment described Laverty was based Edison’s need to
know about the sludge left the bottom the electroplating baths make nickel
flake. The idea was to
crystallize the solution provide hard recording surface. His
laboratory notebook records the mixing chemicals and his letters indicate that
he worked condensite.
627 Laverty correspondence Historian’s Note 90. Paul Laverty worked both condensite for phonograph records and
on the nickel flake used the Edison storage battery.627 tested his lithium titration, method determining
a constituent mixture volumetric analysis), using the burettes seen in
211
.Table Record/Battery Experiments. mixed shellac and
tetrachlomapthalene with numerous solvents and kept record the results.
624 Notebook N-10-07-29.
4522 Notebook N-09-04-20. Legal
difficulties prevented Edison from using celluloid and forced him find a
substitute. know lot about the work this
table because the experimenter who worked here from 1909 1910 left several
letters about his activities.3.
625 Notebook N-ll-00-00. Both were
inferior when compared celluloid and phenol resins.626
Laverty’s co-worker this table, Paul Christiansen, produced lithium which was
used batteries.624
Laverty was also involved experiments phenol-based record materials.
Historian’s Note 68
