IMPROVEMENTS IN HARMONIUMS
Year: 1861

page_text: PROVISIONAL SPECIFICATION left by Henry Thomas Wedlake at the
Office of the Commissioners of Patents, with his Petition, on the 27th
April 1861.
I, HENRY THOMAS WEDLAKE, of 327, Euston Road, and 58, Warren Street,
Tottenham Court Road, do hereby declare the nature of the Invention
for "IMPROVEMENTS IN HARMONIUMS," to be as follows:-
This Invention has for its object improvements in harmoniums. Before
proceeding to describe the nature of my Invention, it is necessary for me to
explain shortly the construction of the harmonium:-The harmonium is a
wind instrument in which the sound is in all cases produced without
the aid of pipes, and simply by means of metal tongues put into
vibration by a current of air forced past them, and also in. which pallets
or valves capable of being opened and shut by finger keys on a key board
are employed to regulate the passage of compressed air from a reservoir
past these tongues. The pallets or valves in the -harmoniums are in all
cases put beyond the vibrating tongues, that is to say, each vibrating tongue
is placed in a passage communicating with the wind chest, and fitted at its
further end with a pallet or valve beyond the vibrating tongue, so that the
tongue while the instrument is in use is always surrounded by compressed
air, which commences to flow past the tongue to cause it to sound as soon
as the valve or pallet at the end of the passage is lifted. The wind chest
of the harmonium is so constructed that the pressure of the wind in it can

page_text: be regulated as required while using the instrument, the pressure of the wind
increasing as the quantity in the wind chest increases.
My Invention consists in constructing harmoniums with two wind chests,
the one to contain wind at a higher pressure than the other, so that the
vibrating tongues in the bass of the instrument may be supplied with wind
at a lower pressure than the wind supplied to the vibrating tongues in the
treble of the instrument. I make the two wind chests each with its own
feeder or supply bellows, but by means of suitable valves when the wind in
the lower pressure wind chest runs low, this wind chest is supplied from
the high-pressure wind chest. In harmoniums having two or more stops,
that is to say, two or more vibrating tongues for each finger key, each set or
stop of vibrating tongues is arranged over a chamber of its own, to which
the wind is admitted from the wind chest when the vibrating tongues of the
set or stop are to be brought into action; for this purpose a valve is opened;
this has heretofore been done by means of instruments actuated directly by
the performer, who for this purpose has to remove his hands from the key
board. Now according to my Invention the performer does not open the
valve which is required open directly, but by means of a button or lever (so
placed that it can be readily touched by the performer without requiring
him to remove his bands from the finger keys) he opens a small valve, which
allows air to pass from the wind chest to inflate a bellows-formed chamber,
and this instrument during its inflation actuates the valve by which the wind
passes to the chamber beneath the set or stop of vibrating tongues which it
is desired to call into use. The button or lever above mentioned requires
but a very slight force to move it, and it only travels through a short distance
so that it can be used by the performer without any interruption of the per-
formance, an interruption which is unavoidable with the ordinary draw stop.
Another similar button or lever, when acted on, allows the wind to escape
from the bellows-formed instrument, which then collapses and closes the valve
before mentioned. When the stops in the harmonium are numerous, I make
use of buttons or levers and bellows-formed instruments, so arranged as to
open more than one valve, and thus to bring more than one stop into action,
so that the touching a single button or lever brings into action a combination
of stops which it is desired to employ; the connections are so made also that
these latter buttons or instruments, in addition to opening the valves for the
stops required for use, close the valves of all the other stops. To avoid the
use of a large number of these combination buttons or levers, I só arrange
them that they may each be used to bring on either one of several combi-

page_text: nations of stops, there being moveable parts in connection with the buttons
or levers which are set beforehand or at any convenient time, so as to
determine which of the combinations the button or lever when acted on shall
bring into operation. In order to blow harmoniums I employ bellows actuated
by clockwork and arranged within the seat for the performer; these bellows
communicate with the wind chest or chests by a flexible tube or tubes.