Miscellaneous Inventions - 7

Miscellaneous Inventions - 7

 From one of the preceding items it will be noted that even in the eighties Edison

perceived much advantage to be gained in the line of economy by the use of lamp

filaments employing refractory metals in their construction. From another caveat, filed in

1889, we extract the following, which shows that he realized the value of tungsten also

for this purpose. "Filaments of carbon placed in a combustion tube with a little chloride

ammonium. Chloride tungsten or titanium passed through hot tube, depositing a film of

metal on the carbon; or filaments of zirconia oxide, or alumina or magnesia, thoria or

other infusible oxides mixed or separate, and obtained by moistening and squirting

through a die, are thus coated with above metals and used for incandescent lamps.

Osmium from a volatile compound of same thus deposited makes a filament as good as

carbon when in vacuo."

In 1888, long before there arose the actual necessity of duplicating phonograph records so

as to produce replicas in great numbers, Edison described in one of his caveats a method

and process much similar to the one which was put into practice by him in later years. In

the same caveat he describes an invention whereby the power to indent on a phonograph

cylinder, instead of coming directly from the voice, is caused by power derived from the

rotation or movement of the phonogram surface itself. He did not, however, follow up

this invention and put it into practice. Some twenty years later it was independently

invented and patented by another inventor. A further instance of this kind is a method of

telegraphy at sea by means of a diaphragm in a closed port-hole flush with the side of the

vessel, and actuated by a steam-whistle which is controlled by a lever, similarly to a

Morse key. A receiving diaphragm is placed in another and near-by chamber, which is

provided with very sensitive stethoscopic ear-pieces, by which the Morse characters sent

from another vessel may be received. This was also invented later by another inventor,

and is in use to-day, but will naturally be rivalled by wireless telegraphy. Still another

instance is seen in one of Edison's caveats, where he describes a method of distilling

liquids by means of internally applied heat through electric conductors. Although Edison

did not follow up the idea and take out a patent, this system of distillation was later hit

upon by others and is in use at the present time.

In the foregoing pages of this chapter the authors have endeavored to present very briefly

a sketchy notion of the astounding range of Edison's practical ideas, but they feel a sense

of impotence in being unable to deal adequately with the subject in the space that can be

devoted to it. To those who, like the authors, have had the privilege of examining the

voluminous records which show the flights of his imagination, there comes a feeling of

utter inadequacy to convey to others the full extent of the story they reveal.

The few specific instances above related, although not representing a tithe of Edison's

work, will probably be sufficient to enable the reader to appreciate to some extent his

great wealth of ideas and fertility of imagination, and also to realize that this imagination

is not only intensely practical, but that it works prophetically along lines of natural

progress.