IMPROVEMENTS IN MAGNETIZING METAL OR OTHER SUBSTANCES, AND UTILISING SAME FOR PRODUCING MAGNETIC, ELECTRIC, TELEPHONIC, MICROPHONIC, AND ACOUSTIC EFFECTS
Year: 1878

page_text: "6
LETTERS PATENT to George Edward Pritchett, of Bishop's Stortford, in
the County of Herts, Architect, for the Invention of IMPROVEMENTS IN
MAGNETIZING METAL OR OTHER SUBSTANCES, AND UTILISING SAME FOR
PRODUCING MAGNETIC, ELECTRIC, TELEPHONIC, MICROPHONIC, AND ACOUSTIC
EFFECTS
"
Sealed the 10th January 1879, and dated the 13th July 1878.
PROVISIONAL SPECIFICATION left by the said George Edward Pritchett at
the Office of the Commissioners of Patents on the 13th July 1878.
"
GEORGE EDWARD PRITCHETT, of Bishop's Stortford, in the County of Herts,
Architect. IMPROVEMENTS IN MAGNETIZING METAL OR OTHER SUBSTANCES, AND
UTILISING SAME FOR PRODUCING MAGNETIC, ELECTRIC, TELEPHONIC, MICROPHONIC,
AND ACOUSTIC EFFECTS."
This Invention mainly comprises means of magnetising plates of metal or other
substances, either flat or curvilinear (as distinguished from magnetizing solid bars).
These plates may receive coils or otherwise, the effects of which when used with
rods or bars are well known.
In combination with these plates and apparatus one, two, or more pieces of carbon,
carboniferous substances, quicksilver, or other suitable material may be introduced,
in such a manner as to assist or strengthen the transmission or reception of sounds
pervading or passing through air or materials, or otherwise, by means of the instru
ments.
-
Stethoscopic instruments may be utilized by such a combination for medical or
other purposes, and by my Invention deaf and other people may be assisted in
hearing.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent filed by
the said George Edward Pritchett in the Great Seal Patent Office on the
13th January 1879.
GEORGE EDWARD PRITCHETT, of Bishop's Stortford, in the County of Herts,
Architect. "IMPROVEMENTS IN MAGNETIZING METAL OR OTHER SUBSTANCES, AND
UTILIZING SAME FOR PRODUCING MAGNETIC, ELECTRIC, TELEPHONIC, MICROPHONIC,
. AND ACOUSTIC EFFECTS."
This Invention comprises means of maguetizing plates of metal or other
substances, either flat or curvilinear (as distinguished from magnetizing solid bars).
These plates may receive coils or otherwise, the effects of which when used with
rods or bars are well known.
In combination with these plates and apparatus one, two, or more pieces of carbon,
carboniferous substances, quicksilver, or other suitable material may be introduced,
in such a manner as to assist or strengthen the transmission or reception of sounds
pervading or passing through air or materials, or otherwise, by means of the instru-
ments.
Stethoscopic instruments may be utilized by such a combination for medical or other
purposes, and by my Invention deaf and other people may be assisted in hearing.
Having thus far described my Invention I may remark that my improved means of
magnetizing plates of metal is effected by forming square, oblong, polygonal, circular,
or elliptical plates of metal, of steel or otherwise, of such thicknesses as will readily
admit of their being formed or bent into shapes, as shown on the several Drawings
hereafter referred to, or as required. The steel plates are then hardened so as to
receive and retain magnetism, my object principally being to obtain coercitive
force, and strong polarity at the centres of shaped plates, and which are raised into
parabolic and segmental or polygonal forms.
I place the centres of these plates on the end of a magnet and make passes so as
to get (after the magnetizing) co-excitive force and strong polarity aforsaid at their
centres.
The magnetic needle is not only strongly deflected but it also strongly follows
and points to the centres as the needle is passed round the centre of the plates,
and any iron plates intervening become magnetized by my process. I can obtain
either north or south polarity or both, as desired.
For the new adaptations and combinations aforesaid, one mode I adopt is to form
several of the said plates into shapes required, and after magnetizing the steel plates
as aforesaid, to place a number of them (both steel and iron if required), together or
at intervals.
As thin plates of hardened steel can be more regularly and strongly magnetized
than thick plates of hardened steel, I secure or screw these plates together, or
as required, thus gaining a stronger magnetic field than could be obtained by
using solid thick plates of steel, which would be difficult and expensive to manu-
facture into the shapes required.
One adaptation and combination is shown in Fig. 1, Sheet I., where a number
of circular and curvilinear magnetized plates, or otherwise, are put together of
resonating form, and this arrangement being of parabolic curve all sounds produced
by electric action in combination with my microphonic appliances are brought to
a focus at A.
In combination with this parabolic resonating form a microphonic arrangement
is introduced, as shown at B, and a coil or coils of wire is or are placed. on the
plates at A, or they, as also their coils, may be placed between the plates: These
coils and microphonic arrangements in combination are joined up with one or
more electric circuits; thus Fig. 1 forms a transmitting and receiving instrument.
The dotted lines at A show an ear piece attached when the arrangement shown
by Fig. 1 is used only for receiving purposes.

page_text: The microphonic combination, shown at B, consists of two pieces of carboniferous
matter; the outer piece is drilled into a conical shape, and the inner piece has a
knife edge, serrated or otherwise, and is suspended from the spring or wire at C..
This wire or spring regulates to a great nicety the pressure between the two pieces
of carbon or other substances aforesaid, as may be introduced; thus by drawing out
or pushing in the handle D. the inner piece of carbon will rise or fall; the curved
dotted line below C shows its dropping and raising action.
Fig. 2 shows the form and top of the magnetized plates, as also other plates, as
required, both for Figs. 1 and 3.. These plates are cut or divided towards their
centres; coercitive force and intense polarity aforesaid is found at E.
In Fig. 1 a coil of wire is shown placed at A; in Fig. 3 a coil of wire is shown
placed at F, but I do not confine myself to place coils at the points shown. The
disposition of the coils may be varied according to the number of the plates.
Fig. 3 shows a lever arrangement for adjusting the combined microphonic
arrangement alluded to, also a demi-resonting form of magnetized or other plates
as required. The dotted lines at A show ear pieces (if required).
Figs. 4, 5, and 6 show two adaptations for the use of the magnetized and other
plates aforesaid. The microphonic combinations are the same as in Figs. 1 and 3,
Sheet I, but the coils are placed differently and the shape and position of the
magnetized or other plates is varied, but the division and combination and con-
struction of the plates is similar to Figs. 1-2, and 3,-Sheet I--
Another adaptation and combination I adopt is shown on Fig. 1, Sheet II.,
whereby a strong magnetized magazine coercitive force or field is formed by
folding a steel plate or plates at the ends A, A, which ends are magnetized. Covered
wire is laid in one or all of the spaces B, B, left between the folds aforesaid, on
the plates C, C, hereafter described. These layers of wire are joined up and are
connected with one or more microphonic electric circuits in the usual way.
In combination with the folded plates aforesaid one, two, or more plates are
introduced between the said plates, as shown at C, C, by the thick black lines; these
plates are cut so as to form vibrating tongues, shown in Fig. 2, Sheet II., which are
left free at one end, the upper plate A being partly removed so as to show the
plates C, C. These tongues may be led to, or near to, the top or bottom plates, or
wires may be led from them to my stethoscopic instrument and disc shown in
Fig. 5. By applying these arrangements shown by Figs 1 and 2, Sheet II., to the
ears, strong acoustic and telephonic effects will be produced. The size of these
plates may be varied to any extent; conical ear tubes may be placed on these plates
instead of applying the ears to the plates.
The handle D is carried down so as to receive a microphonic transmitting cup, as
shown at Fig. 4, Sheet II., as required.
Another adaptation and combination is shown at Fig. 3, Sheet II., being simply
a modification in a circular form of Figs. 1 and 2, Sheet II. Coils of wire are
attached at E, E, which may be protected by a cap F. This Fig. 3 is held by the
handle D to the ear, and the handle D is extended to receive my microphonic cup
as shown at Fig. 4, Sheet II.
Another combination and adaptation I make use of is shown by Fig. 4, Sheet II.,
which is a dual instrument for transmitting and receiving purposes. This instru-
ment has resonating magnetized as also other plates and ear pieces at A, similar
in construction to Fig. 1, Sheet I., and has a microphonic transmitting cup of
ebonite, metal, or other suitable material at B; thus no shifting of the instrument
is necessary, as it can be applied by holding the handle D to the ear and mouth at
the same time and with one motion.
The handle D is jointed so that the instrument can be adjusted to any person's
form of face. This dual arrangement is set forth in Fig. 1, Sheet I., of my Specifica-
tion No. 191, January 15th, 1878. Also Figs. 1 to 6 inclusive in Sheet I. of the
Drawings accompanying this Specification are adapted to be applied to or fixed
to the ears or otherwise, as is set forth in Fig. 3 on Specification of the aforesaid
Patent.
•

page_text: The microphonic cup B may be extended as shown by dotted lines, and the
carboniferous matter or blocks may be placed on a disc of parchment or other
substance in the cup, as shown in Fig. 5.
Another combination and adaptation I make use of is shown by Fig. 5, Sheet II.
Steel magnetized plates as aforesaid, as may also other plates, are formed into a
circular or other shape as described in Fig. 3, and are made to produce a stethoscopic
form of instrument.
In combination with this instrument a microphonic arrangement as shown at F
is introduced.
The carbon block F is attached to parchment which is strongly strained at the
base of the stethoscopic instrument, as shown at G.
Instead of parchment thin metal or any suitable material may be used, so as to
be slightly elastic, or it may be made rigid.
The inner carbon of F is supported by a covered wire and connected with the lever
handle for adjustment at H. Wire coils are placed at I either outside or inside, or
at the top or bottom of Fig. 5, and metal caps fixed to enclose and protect the
coils.
The area of vibration may be increased or diminished as required. This instru-
ment may be applied for medical and other purposes, and deaf and other persons
may be assisted in hearing by using it as well as by using my other instruments
referred to.
The microphonic arrangement F can be brought into action of extreme delicacy
by use of the lever H, or by variation of pressure on the elastic bottom at the time
of auscultation or when speaking, or other use.
The dotted lines at K denote that the base of the stethoscopic instrument may be
made of smaller diameter.
The stethoscopic instrument may be made in one piece, or in layers of steel and
magnetized as aforesaid, as may also the other instruments.
Sonorous vibrations produced in the aforesaid modifications of my instruments
may be reinforced and amplified by sounding boxes, casings, or tubings, the action
of which are well known.
Having now particularly described and ascertained the nature and object of the
said Invention, and in what manner the same is to be performed or carried out in
practice, I would now remark that although the said Invention is open to variation
in detail as to the number, size, position, and shape of the plates of microphonic
arrangements, and joining up of the circuits, and the use or disuse of some arrange-
ments herein-before described or referred to, I hereby declare that I claim sub-
stantially as herein-before set forth and described, the Invention of improvements
in magnetizing metal or other substances, and utilizing same for producing magnetic,
electric, telephonic, microphonic, and acoustic effects.
In witness whereof, I, the said George Edward Pritchett, have hereunto set
my hand and seal, this Thirteenth day of January, in the year of our
Lord One thousand eight hundred and seventy-nine.
G. E. PRITCHETT. (L.S.)