IMPROVEMENTS IN OR APPLICABLE TO MICROPHONES to be as follows:-
Year: 1884

page_text: I ALFRED JULIUS BOULT of 323 High Holborn in the County of Middlesex,
Engineer do hereby declare the nature of the said invention for "IMPROVEMENTS
IN OR APPLICABLE TO MICROPHONES to be as follows:-
"
This invention is chiefly designed for use in microphones of the class described
in an application for Letters Patent by Kazimir Stanislas Dembinski No 7312
of 1884.
The "carbons" employed in practising the above mentioned invention may
according to the present improvements, be rods or pencils of preferably pure
plumbago pressed or otherwise formed into suitable shape or they may consist of a
mixture of plumbago and Indian ink finely ground, mixed and formed into suitable
rods or pencils. Instead of making the "carbons" of the same substance throughout
they may have a core or centre of platinum wood or similar material covered with
the plumbago caused to adhere thereto by glue or other suitable adhesive in some
cases the core or centre is made of brass covered with the platinum and gold ;
a mixture of platinum and plumbago may also be used.

page_text: COMPLETE SPECIFICATION.
I, ALFRED JULIUS BOULT, 323 High Holborn, Middlesex, Engineer, do
hereby declare the nature of the said invention for "IMPROVEMENTS IN OR
APPLICABLE TO MICROPHONES" (a communication from abroad by Kazimir Stanislas
Den binski, Officer in the Belgian Army, Brussels, Belgium,) and in what manner
the same is to be performed, to be particularly described and ascertained in and
by the following statement:-
This invention is chiefly designed for use in microphones of the class described
in an application for Letters Patent by Kazimir Stanislas Dembinski No 7312
of 1884.
"
The "carbons employed in carrying out the invention described in the
Specification and drawings of the above numbered Letters Patent may according
to the present improvements be rods or pencils of preferably pure plumbago
pressed or otherwise formed into suitable shape, or they may consist of a mixture
of plumbago and indian ink finely ground, mixed and formed into suitable rods or
pencils. Instead of making the "carbons" of the same substance throughout they
may have a core or centre of platinum, wood or similar material covered with the
plumbago caused to adhere thereto by glue or other suitable adhesive, in some cases
the core or centre is made of brass covered with the platinum and gold; a mixture
of platinum and plumbago may also be used.
Having now particularly described and ascertained the nature of the said
Invention and in what manner the same is to be performed, as communicated to
me by my foreign correspondent, I declare that what I claim is
1st. The use in microphones, such as are described in the Specification of Letters
Patent No 7312 of 1884 of carbons in the form of rods or pencils composed of pure
plumbago or of plumbago and indian ink with or without a core or centre of wood,
platinum or other material.
2nd. A "carbon" for use in a microphone in the form of a rod or pencil having
a core or centre (of platinum wood or brass covered with platinum and gold or of
other suitable material) covered with plumbago, substantially as described.
Dated this sixth day of March 1885.