" Yet these type experiments became rarer the
1890s progressed; there was longer the time money find
a substitute for ivory, rubber, silk, mother pearl. The research effort was concentrated into
these three basic areas, Table illustrates:
. Edison's strategy was spread his money and
experiments over group projects and use the profits one
to finance the development another.VI-12
with several research and manufacturing operations running at
the same time. Yet order finance
the manufacturing well the R&D the phonograph and ore
separation, Edison had cut back some the more
speculative efforts underway. Work was ended the cotton
picker and the hearing aid.^
The Edison enterprise began the 1890s the foundation
of three main businesses: phonographs, ore separation, and
electrical products. Some projects would practical campaigns,
based identified problems with known goals, and others would
be more speculative basic research with clearly defined
objectives. The pyro-magnetic generator was
abandoned. Edison still maintained long-term speculative
experiments for his own personal interest; including
experiments etheric force and other electromagnetic
phenomena that had been suggested his study the "Edison
Effect
