Improvements in Recording Apparatus.
Year: 1895

page_text: Date of Application, 5th Aug., 1995
Complete Specification Left, 26th Mar., 1896-Accepted, 2nd May, 1896
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Complete Specification Left, 26th Mar., 1896-Accepted, 2nd May, 1896
Improvements in Recording Apparatus.
A communication from abroad by ALBERT CUSHING CREHORE, of Dartmouth
College, Hanover, Grafton Co., New Hampshire, United States of America,
Professor of Physics.
1, WILLIAM LLOYD WISE, of 46 Lincoln's Inn Fields, in the County of London,
Consulting Engineer and Chartered Patent Agent, do hereby declare the nature of
this invention to be as follows:-
This invention relates to electrical recording apparatus whereby the occurrence
of incidents or events at fixed or variable intervals may be made a matter of
record.
The main object of the invention is the production of a device which will be
capable of performing the functions of such well known apparatus as the Morse
register, the Thomson syphon recorder, and chronographs wherein by the aid of the
electric current a record is made by a magnetically controlled stylus or by the
action of an electric spark.
Another object of the invention is to adapt such device to the purpose of
measuring the velocity of moving bodies such as projectiles.
In such a device it is essential that the production of the record should follow
instantly upon the occurrence of the event, but in most of those heretofore constructed
it has been necessary to put into motion some ponderable object, such as the stylus
in a Thomson syphon recorder, thereby causing an appreciable interval between
the occurrence and the recording thereof; or the record produced has not been
sufficiently clear to enable computations to be accurately made therefrom.
In the present device a beam of light is the active recording agent-an imponder-
able means requiring no appreciable time to bring it into action. This beam of
light is caused to fall upon a sensitized plate where its persistence and interruptions
are clearly recorded.
Then to manipulate this beam without employing a ponderable shutter, I polarize
said beam and, by rotating its plane of polarization through the aid of a magnetic
field, produce interruptions therein as desired.
This magnetic field might be produced and presented to and withdrawn from the
medium affected thereby in any suitable way but that deemed most desirable
consists in placing an electric coil or coils about said medium and creating and
withdrawing the field by making and breaking the circuit of the coil or coils.
Such recording instrument may then be adapted to any use wherein it is desired
to make a record of the makes and breaks in an electric circuit, and by the proper
uniform relative movement being given to the beam and the sensitized plate the
exact relation of the makes and breaks will be recorded.
From the photograph produced, the meaning of the changes or interruptions in
the circuit may be ascertained and from the relation between said uniform movement
and the reproduced interruptions or changes of the beam of light the time between
them may be readily computed.
The invention consists in the combination with means for polarizing beam of
light, of a medium interposed in said beam and acting when in a magnetic field to
rotate the plane of polarization thereby causing an interruption in the beam of light,
an electric circuit controlling the effect of said field in response to pulsations or to

page_text: makes and breaks in the circuit, and photographic apparatus for producing a record
of the interruptions in the beam of light.
The invention also consists in the combination with apparatus for producing an
interruption in a ray of light, of means for photographing the presence of the ray,
an electric circuit co-operating with said apparatus and extending along the path
of a moving body, and means operated upon by said body in its movement for
controlling said circuit.
My invention further consists in the construction, arrangement and combination
of parts as hereinafter fully set forth.
In the drawings which accompany this Specification and form a part thereof;
Fig. 1, diagramatically represents the chronographic part of the apparatus.
Fig. 2, represents diagramatically the apparatus for measuring the velocity of
moving bodies.
Fig. 3, represents graphically a photograph of a repeatedly interrupted ray
of light.
As above set forth the invention may be applied to the production of a record
of any incident or occurrence which can affect the flow of current over an electric
circuit. The makes and breaks or other variations in the flow of such current may
be produced manually or automatically as the circumstances of the application of
the invention may require. 1 will describe the invention as used in measuring the
velocity of a projectile.
In the drawings, S, represents the screen provided with an opening of suitable
size to admit the necessary ray or beam of light from some powerful source, as the
sun or an arc lamp. P and A, represent Nicol's prisms acting respectively as
polarizer and analyzer, the latter being set for darkness. Between P and A, may
be located any suitable agent or medium possessing the property of rotating the
plane of polarization of a beam of light by the action of a magnetic field. For
this purpose I have shown at T, a tube containing liquid bisulphide of carbon
which answers the purpose perfectly. L, is a lens and D, is a rotary disc for
supporting a sensitized film or plate. This disc is mounted in a dark box provided
with a suitable slit as at H, and may be rotated by any power which will produce
a constant uniform movement.
The means for producing a magnetic field about the polarizing agent at T, is
preferably a coil or coils of insulated wire. These coils are in the electric circuit E,
wherein is a battery or other suitable source of current indicated at B, and a switch
indicated at C.
G, indicates a gun, the velocity of whose projectile is to be determined.
The circuit E, is extended along each side of the path of the projectile and cross
or shunt connections F, are placed in said path at stated intervals, so that as the
projectile travels may break or interrupt the current in one after the other of
said connections. Between the adjacent connections F, which simply typify any
means of breaking or interrupting the flow of current over the circuit, are placed
suitable devices for re-establishing the circuit.
One means for this purpose consists of a pair of springs located in one side of
the main circuit E, as at , which are normally held apart by a plug of insulation 4,
from which a suitable connection 2, extends into the path of the projectile. Such
connection may consist of a wire attached at its free end to a suitable weight or to
some fixed object so that as the projectile strikes the wire the plug will be pulled
from between the springs r, and the circuit closed at that point.
The lens L, may be interposed to concentrate the rays of light upon the plate D,
but it is not essential.
The sensitized plate is indicated as having a rotary motion but its motion may
be of any sort provided the law thereof is known and points upon the plate have a
definite known time of passing the opening.
The operation is as follows:-As soon as the current is turned on, its passage
through the coil causes light to appear through the analyzer and to persist so long
as the current is on. Then upon the firing of the gun the projectile cuts the wire F,

page_text: at the muzzle and so interrupts the current causing the light through A, to
completely vanish. When the projectile arrives at , the plug z, will be pulled
out, allowing the circuit to be made again and current to flow over the next cross
connection F. This makes the light appear again on the plate, to be again suddenly
cut off when the projectile cuts the next wire F, and again caused to appear as the
projectile pulls the next, plug r, and so on, causing a number of makes and breaks
in the beam of light and thereby recording the intervals between different positions
of the projectile.
If the photographic plate is revolved the circle of light produced thereon is
interrupted at intervals and by the angle through which the plate turns from one
interruption to another, the time. and from it the velocity, of the projectile is
measured.
By the diagram in Fig. 3, is represented the photograph produced by the
operation of the above described apparatus in measuring the velocity of a projectile
travelling the path as represented in Fig. 2.
The broken ring R, represents the reproduction of the intermittent beam of
light. The disc D, having been started in its rotation and having acquired a
uniform rotation of for instance 12 or 13 turns a second the slide was drawn as at a,
the wire F, at the muzzle cut by the projectile as at b, the first plug drawn as at c,
the second wire, five feet from the muzzle, cut as at 5, the second plug y, drawn as
at d, the third wire F, ten feet from the muzzle, cut as at 10, and so on interrupting
the circuit at 15, 20, 30, 35, 40, 45 and 95 feet respectively from the muzzle of the
gun, said circuit being made between the breaks as set forth. From the photo-
graphic record of the breaks in the circuit, which produce sharp lines as indicated,
the velocity of the projectile during any interval can be accurately determined.
By this means the fact was proven that the velocity of a projectile increases during
the first five or ten feet after leaving the muzzle.
There are many changes that may be made in the selection, arrangement and
combination of parts for carrying out the invention and I do not therefore limit
myself to those specifically mentioned and described.
Polarizing a beam of light and rotating the plane of polarization, by the action
of a medium interposed between the polarizer and analyzer and subjected to the
action of a magnetic field, were matters of laboratory experiment with Faraday,
and this part of the apparatus is not claimed by me.
Dated this 6th day of August 1895.
W. LLOYD WISE,
46 Lincoln's Inn Fields, London, W.C., Chartered Patent Agent.
Improvements in Recording Apparatus.
A communication from abroad by ALBERT CUSHING CREHORE, of Dartmouth
College, Hanover, Grafton Co., New Hampshire, U.S.A., Professor of
Physics).
1, WILLIAM LLOYD WISE, of 46, Lincoln's Inn Fields, in the County of
London, Consulting Engineer and Chartered Patent Agent, do hereby declare
the nature of this invention and in what manner the same is to be performed to be
particularly described and ascertained in and by the following statement:
This invention relates to electrical recording apparatus whereby the occurrence
of incidents or events at fixed or variable intervals may be made a matter of
record.
The main object of the invention is the production of a device which will be
capable of performing the functions of such well known apparatus as the Morse-

page_text: register, the Thomson syphon recorder, and chronographs wherein by the aid of
the electric current a record is made by a magnetically controlled stylus or by the
action of an electric spark.
Another object of the invention is to adapt such a device to the purpose of
measuring the velocity of moving bodies such as projectiles.
In such a device it is essential that the production of the record should follow
instantly upon the occurrence of the event, but in most of such devices as heretofore
constructed it has been necessary to put into motion some ponderable object, such
as the stylus in a Thomson syphon recorder, thereby causing an appreciable interval
between the occurrence and the recording thereof; or the record produced has not
been sufficiently clear to enable computations to be accurately made therefrom.
In the present device a beam of light is the active recording agent-an
imponderable means requiring no appreciable time to bring it into action. This
beam of light is caused to fall upon a sensitized plate where its persistence and
interruptions are clearly recorded.
To manipulate this beam without employing a ponderable shutter, I polarize
said beam and, by rotating its plane of polarization through the aid of a magnetic
field, produce interruptions therein as desired.
This magnetic field might be produced and presented to and withdrawn from
the medium affected thereby in any suitable way, but that deemed most desirable
consists in placing an electric coil or coils about said medium and creating and
withdrawing the field by making and breaking the circuit of the coil or coils.
Such a recording instrument may then be adapted to any use wherein it is
desired to make a record of the makes and breaks in an electric circuit, and by the
proper uniform relative movement being given to the beam and the sensitized
plate, the exact relation of the makes and breaks will be recorded.
From the photograph produced, the meaning of the changes or interruptions in
the circuit may be ascertained, and from the relation between said uniform
movement and the reproduced interruptions or changes of the beam of light, the
time between them may be readily computed.
The invention consists in the combination with means for polarizing a beam of
light, of a medium interposed in said beam and acting when in a magnetic field to
rotate the plane of polarization, thereby causing an interruption in the beam of
light, an electric circuit controlling the effect of said field in response to pulsations
or to makes and breaks in the circuit, and photographic apparatus for producing a
record of the interruptions in the beam of light.
The invention also consists in the combination with apparatus for producing an
interruption in a ray of light, of means for photographing the presence of the ray,
an electric circuit co-operating with said apparatus and extending along the path
of a moving body, and means operated upon by said body in its movement for
controlling said circuit.
My invention further consists in the construction, arrangement and combination
of parts as hereinafter fully set forth.
Referring to the drawings filed with my Provisional Specification,
Fig. 1, diagrammatically represents the chronographic part of the apparatus.
Fig. 2, represents diagrammatically the apparatus for measuring the velocity of
moving bodies.
Fig. 3, represents graphically a photograph of a repeatedly interrupted ray of
light.
As above set forth the invention may be applied to the production of a record
of any incident or occurrence which can affect the flow of current over an electric
circuit. The makes and breaks or other variations in the flow of such current
may be produced manually or automatically as the circumstances of the application
of the invention may require. I will describe the invention as used in measuring
the velocity of a projectile.
In the drawings, S, represents a screen provided with an opening of suitable
size to admit the necessary ray or beam of light from some powerful source, as the
.

page_text: sun or an arc lamp. P and A, represent Nicol's prisms acting respectively as
polarizer and analyzer, the latter being set for darkness. Between P and A, may
be located any suitable agent or medium possessing the property of rotating the
plane of polarization of a beam of light by the action of a magnetic field. For
this purpose I have shown at T, a tube containing liquid bi-sulphide of carbon
which answers the purpose perfectly. L, is a lens and D, is a rotary disc for
supporting a sensitized film or plate. This disc is mounted in a dark box provided
with a suitable slit as at H, and may be rotated by any power which will produce
a constant uniform movement.
The means for producing a magnetic field about the polarizing agent at T, is
preferably a coil or coils of insulated wire. These coils are in the electric circuit E,
wherein is a battery or other suitable source of current indicated at B, and a
switch indicated at Č. G, indicates a gun, the velocity of whose projectile is to
be determined.
The circuit E, is extended along each side of the path of the projectile and
cross or shunt connections F, are placed in said path at stated intervals, so that
as the projectile travels it may break or interrupt the current in one after the other
of said connections. Between the adjacent connections F, which simply typify
any means of breaking or interrupting the flow of current over the circuit, are
placed suitable devices for re-establishing the circuit.
One means for this purpose consists of a pair of springs located in one side of
the main circuit E, as at X, which are normally held apart by a plug of
insulation y, from which a suitable connection, extends into the path of the
projectile. Such connection may consist of a wire attached at its free end to a
suitable weight or to some fixed object so that as the projectile strikes the wire the
plug will be pulled from between the springs, and the circuit closed at that
point.
The lens L, may be interposed to concentrate the rays of light upon the plate D,
but it is not essential.
The sensitized plate is indicated as having a rotary motion, but its motion may
be of any sort provided the law thereof is known and points upon the plate have a
definite known time of passing the opening.
as the current is on.
The operation is as follows:-As soon as the current is turned on, its passage
through the coil causes light to appear through the analyzer and to persist so long
Then upon the firing of the gun the projectile cuts the
wire F, at the muzzle and so interrupts the current causing the light through A,
to completely vanish. When the projectile arrives at the first connection z, the
plug y, will be pulled out, allowing the circuit to be made again and current to
flow over the next cross connection F. This makes the light appear again on the
plate, to be again suddenly cut off when the projectile cuts the next wire F, and
again caused to appear as the projectile pulls the next plug x, and so on, causing a
number of makes and breaks in the beam of light and thereby recording the
intervals between different positions of the projectile.
If the photographic plate is revolved, the circle of light produced thereon is
interrupted at intervals and by the angle through which the plate turns from one
interruption to another, the time, and from it the velocity, of the projectile is
measured.
By the diagram in Fig. 3, is represented the photograph produced by the
operation of the above described apparatus in measuring the velocity of a projectile
travelling the path as represented in Fig. 2.
The broken ring R, represents the reproduction of the intermittent beam of
light. The disc D, having been started in its rotation and having acquired a
uniform rotation of for instance 12 or 13 turns a second, the slide was drawn as
at a, the wire F, at the muzzle cut by the projectile as at b, the first plug drawn as
at c the second wire, five feet from the muzzle, cut as at 5, the second plug y, drawn
as at d, the third wire F, ten feet from the muzzle, cut as at 10, and so on
interrupting the circuit at 15, 20, 30, 35, 40, 45 and 95 feet respectively from the

page_text: muzzle of the gun, the said circuit being made between the breaks as set forth.
From the photographic record of the breaks in the circuit, which produce sharp
lines as indicated, the velocity of the projectile during any interval can be
accurately determined. By this means the fact was proven that the velocity of a
projectile increases during the first five or ten feet after leaving the muzzle.
There are many changes that may be made in the selection, arrangement and
-combination of parts for carrying out the invention and I do not therefore limit
myself to those specifically mentioned and described.
Polarizing a beam of light and rotating the plane of polarization, by the action
"of a medium interposed between the polarizer and analyzer and subjected to the
action of a magnetic field, were matters of laboratory experiment with Faraday,
and this part of the apparatus is not claimed by me.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim in recording apparatus is :-
1. The combination with a polarizer for producing a beam of plane polarized
light, of an analyzer in line therewith, a medium substantially such as described
in a magnetic field located between the polarizer and analyzer, the plane of
polarization of said beam being rotated under the influence of said field, and a
recorder for a beam of light emerging from the analyzer, substantially as set
forth.
2. The combination of a polarizer, an analyzer, a medium such as described
placed between them and adapted to rotate the plane of polarization under the
influence of a magnetic field, electrical means for producing a magnetic field,
circuit controlling devices for operating thereon at intervals, and a photographic
recorder of the beam of light emerging from the analyzer, said recorder and beam
of light moving relatively to one another for the purpose specified.
3. The combination with a photographic recording apparatus, of an electrically
controlled device for interrupting a ray of light directed to said apparatus, an
electrical circuit extending from said device along the path of a moving body, and
devices arranged in the path of said body whereby the circuit is operated upon at
fixed intervals as the body moves along, for the purpose seti.
4. The arrangement substantially as described and shown ur the purpose
specified.
Dated this 26th day of March 1806