The phonoplex was a
successful invention that enabled telegraph and telephone
messages sent over the same wire. There was great
demand for phonoplex sets from the railroad industry and Edison
made handsome profits manufacturing the device. His finances
had been stretched the costs building the laboratory and
his great optimism had led him undervalue the expense of
experimentation and overvalue the commercial worth its
product. Among the products
actually manufactured the lab were telegraph signalling
sets, phonographs, electric meters, and chemicals and plates
used storage batteries.
Despite the flow money from paid research, Edison was
still plagued with shortages operating funds. As
soon the phonograph was perfected, the lab was put work
manufacturing the cylinders, both blank and recorded, for the
new machine.11-22
commercial success, but Edison had several highly lucrative
telegraph products hand generate funds." Consequently, Edison
. August 1887 Tate wrote Insull that the task
of building the lab "was going require good deal more
money than was first anticipated. Edison found more economical way
to make India ink and set manufacture West Orange. After
manufacturing the telegraph equipment the machine shops,
Edison sold directly industry.
The availability two large machine shops the
laboratory complex provided the opportunity make money from
manufacturing telegraph instruments
