IMPROVEMENTS IN SPEED INDICATORS and Speed REGULATORS OR GOVERNORS.”
Year: 1875

page_text: LETTERS PATENT to James Murdoch Napier, of York Road, Lambeth,
in the County of Surrey, for the Invention of "IMPROVEMENTS IN
SPEED INDICATORS and Speed REGULATORS OR GOVERNORS.”
PROVISIONAL SPECIFICATION left by the said James Murdoch Napier
at the Office of the Commissioners of Patents, with his Petition,
on the 27th November 1875.
I, JAMES MURDOCH NAPIER, of York Road, Lambeth, in the County
of Surrey, do hereby declare the nature of the said Invention for
"IMPROVEMENTS IN SPEED INDICATORS AND SPEED REGULATORS OR GOVERNORS," to
be as follows :-
The first part of this Invention has for its object improvements in
speed indicators for exhibiting the rate of motion or number of
revolutions being made (say per minute) by a shaft, spindle, wheel, pulley,
or other such rotary body, and by marine, locomotive, and stationary
engines, and generally by engines, machinery, carriages, and instruments
which have rotatory parts or moving parts from which a rotatory action

page_text: •
can be obtained. This part of my Invention has also for its object
improvements in speed indicators for recording the rates of motion or
number of revolutions, as above referred to.
I employ a vessel formed to contain a suitable fluid mounted on a
spindle or in bearings or supports so that it can be easily rotated. The
vessel is rotated by being placed in connection through suitable pullics
and band, toothed gear, or other convenient means with the rotating
body, engine, machine, or instrument, the speed of which it is desired to
indicate, and the fluid when placed within it rotates with it. I provide
a fixed tube or vessel supported by a suitable frame or bracket, the
lower portion of this tube or vessel by preference passes into the rotating
vessel at its upper end and at its axis. From this fixed tube or vessel a
hollow arm projects and terminating near the inner circumference of the
rotating vessel but not touching it. In this hollow arın at or near its
extremity is an orifice through which the fluid in the rotating vessel
find its level in the stationary tube or vessel. The orifice referred to is
so placed that when motion is given to the rotating vessel a portion of
the fluid in it is forced in at the orifice of the stationary tube or vessel,
and as the pressure of the fluid at the orifice is increased by an increase
in the speed of rotation the fluid rises higher in the stationary tube or
vessel, and so the height of the fluid varies according to the speed of
rotation given to the rotating vessel and to the fluid contained in it.
In order to enforce and sustain the rotation of the fluid as completely
as possible in conformity with that of the vessel I provide internal pro-
jections connected with or being part of the rotating vessel. In forming
these projections I leave a space sufficient so that they may not interfere
with the part which projects from the fixed tube or vessel.
It will be understood that the projection used for ensuring the
rotation of the liquid with the vessel ensure at the same time the due
pressure of the liquid at the orifice and the equivalent rise of the fluid
in the indicating tube or vessel. The height of the fluid so raised may
represent in conjunction with a scale the number of revolutions (say per
minute) made either by the rotating vessel or by the engine or body to
which it is connected and the speed of which it is desired to know; the
scale may also be marked for the fluid to indicate miles or other
measures per hour when the instrument is to be used for indicating the
speed of locomotive engines and carriages.

page_text: In some cases I use a glass tube as the indicating tube with scale
attached. This tube may be straight and may risc directly from the
fixed tube or vessel which passes into the rotating vessel, or it may bo
bent downwards after it rises from the fixed vessel but so as to clear the
rotating vessel, and; then upwards, the downward run being sufficiently
low to allow of the liquid rising in the final upward run to the height
of the level of the liquid in the rotating vessel when it is at rest, and so
exhibit the starting or zero point from which the liquid rises. In other
cases I fix a larger tube rising from the fixed tube or vessel which
passes into the rotating vessel. This larger tube may be of glass or of
metal; in it I use a float connected with dial and pointer or other
equivalent indicating means. The rise or fall of the liquid in the tube
will in this case operate the float and so cause the indication of speed by
means of the pointer on the divided dial. I also employ a float with
means attached to indicate the height of the fluid in the stationary tube
or vessel, and consequently the speed of rotation of the rotating vessel
or otherwise, as before explained, of the machine, engine, or body con-
nected with it.
When it is desired to register or record continuously or otherwise the
rate of motion or number of revolutions (say per minute) made or being
made by the rotating vessel, or the machine, engine, or other body con-
nected with it, in such case I employ a time piece arranged in
connection with my speed indicator, so as to present to a pencil actuated
by the float ruled paper on which a diagram is drawn through the
combined actions of the time picce and the float, which diagram forms a
register of the speed of the rotating vessel, or of the machine or engine
or body the speed of which it is desired to register. The ruled paper on
which the register is made may be placed on a drum or cylinder which
is turned by the timepiece while the pencil is moved by the float in a
direction parallel to the access of the cylinder or a dial or disc of paper
ruled in concentric circles, and radiating lines may be used and caused
to turn by a time piece, while the pencil in connection with the float
may operate ou a line from the circumference towards the centre of the
disc or dial. In this case the radiating ruled lines will represent time,
and the concentric circles will represent the speed of rotation.
If preferred the clock movement may be arranged to work the pencil,
or it may work a pointer to pierce the paper, the paper being moved by

page_text: The second part of this Invention has for its object the regulating or
govering of the speed of motive-power engines, such as steam, water,
and other engines which are capable of being governed by the opening
and closing of a valve; I employ a vessel formed to contain a suitable
fluid placed on a spindle or in bearings or supports, so that it can be 5
casily rotated. This vessel is rotated by being placed in connection by
suitable wheels, pullies, or other convenient mechanical means with the
engine the speed of which is to be regulated or governed by it, and the
fluid when placed within it rotates with it. I provide a fixed tube or
vessel supported by a sutable frame or bracket. The lower end or 1
portion of this tube or vessel passes into the rotating vessel, by
preference, at its upper end and at its axis. From this fixed tube or
vessel a hollow arm projects towards and terminates near the inner
circumference of the rotating vessel but not touching it. In this hollow
arm at or near its extremity is an orifice through which the fluid when ]
put into the rotating vessel finds its level in the stationary tube or
vessel. The orifice referred to is so placed that when motion is given to
the rotating vessel a portion of the fluid in it is forced in at the orifice
of the stationary tube or vessel, and as the pressure of the fluid at the
orifice increases by an increase in the speed of rotation, the fluid rises
higher in the stationary tube or vessel, and so the height of the fluid
varies more or less according to the speed of rotation given to the
rotating vessel and to the fluid contained in it.
As in the case of my speed indicator I enforce and sustain the
rotation of the fluid as completely as possible in conformity with that of
the vessel by internal projections connected with or being part of the
rotating vessel. In forming these projections I leave a space sufficient
so that they may not interfere with the part which projects from the
fixed tube or vessel.
It will be understood that as in my speed indicator the projections
used for insuring the rotation of the liquid with the vessel insure at the
same time the due pressure of the liquid at the orifice and the equivalent
rise of the fluid in the fixed tube or vessel.
In order to operate upon the governing or throttle valve of the engine
by means of the rising or falling of the liquid in the stationary tube or
vessel, I employ a float which I connect with the throttle valve of the
engine by means of toothed wheels, pullies, and cords, levers, or other

page_text: ordinary and convenient arrangement, so that when in consequence of
an excess of speed in the engine the fluid is raised above a certain
height in the stationary tube or vessel, the consequent rising of the
float partly or entirely closes the valve and shuts off the steam or other
power. When on the other hand the engine does not run fast enough
the fluid in the stationary tube or vessel falls so that the float is lowered,
and thus the valve is opened to permit more steam or other power to
operate, and thus the engine is kept at the desired rate of speed, the
float may be partly balanced by a weight so that the balance weight
will operate on the valve when the float is raised by the rise of the fluid,
while when it falls the excess in the float over that in the balance
weight will operate on the valve, or the valve may be actuated in one
sense by the float being forced up by the fluid, and in the opposite sense
by the weight of a float on the falling of the fluid.
Mercury, water, or other suitable fluid may be used for my speed
indicator as well as for my regulator or governor.
The rotating vessels for my improved speed indicators as well as for
my improved speed governor may be made cylindrical or of other suitable
form, and may be furnished with a cover or otherwise may be constructed
in two convenient parts securely fixed together to prevent the escape
of the liquid at their junctions, and when a fixed central tube or vessel
passes through a hole in the cover or upper part of the rotating vessel,
and further, when this tube or vessel is firmly supported by a bracket or
frame, it may be fitted to the hole in the cover or upper part of the
rotating vessel, and form a bearing or support to steady the vessel in its
revolutions. When a large float is used, such as will be necessary for
my speed governor I prefer only to enlarge to receive it that part of the
stationary tube or vessel which rises above the rotating vessel leaving
that part which enters the rotating vessel small. If desired however the
full size of the fixed tube or vessel required for the float may pass into
the rotating vessel.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said James Murdoch Napier in the Great Seal Patent
Office on the 27th May 1876.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JAMES
MURDOCH NAPIER, of York Road, Lambeth, in the County of Surrey,
send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-seventh day of November, in
the year of our Lord One thousand eight hundred and seventy-five, in
the thirty-ninth year of Her reign, did, for Herself, Her heirs and suc-
cessors, give and grant unto me, the said James Murdoch Napier, Her
special license that I, the said James Murdoch Napier, my executors,
administrators, and assigns, or such others as I, the said James Murdoch
Napier, my executors, administrators, and assigns, should at any time
agree with, and no others, from time to time and at all times there-
after during the term therein expressed, should and lawfully might
make, use, exercise, and vend, within the United Kingdom of Great
Britain and Ireland, the Channel Islands, and Isle of Man, an Inven-
tion for "IMPROVEMENTS IN SPEED INDICATORS AND SPEED REGULATORS OR
GOVERNORS," upon the condition (amongst others) that I, the said James
Murdoch Napier, my executors or administrators, by an instrument in
writing under my, or their, or one of their hands and seals, should
particularly describe and ascertain the nature of the said Invention,
and in what manner the same was to be performed, and cause the
same to be filed in the Great Seal Patent Office within six calendar
months next and immediately after the date of the said Letters
Patent.
NOW KNOW YE, that I, the said James Murdoch Napier, do hereby
declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, that is to say :-
The first part of this Invention has for its object improvements in
speed indicators for exhibiting the rate of motion or number of revolu-
tions being made (say per minute) by a shaft, spindle, wheel, pulley,
or other such rotatory body, and by marine, locomotive, and stationary

page_text: engines, and generally by engines, machinery, cariages, and instruments
which have rotatory parts or moving parts from which a rotatory action
can be obtained. This part of my Invention has also for its object
improvements in speed indicators for recording the rates of motion or
numbers of revolutions as above referred to.
I employ a vessel formed to contain a suitable fluid mounted on a
spindle or in bearings or supports so that it can be easily rotated. The
vessel is rotated by being placed in connection through suitable pullies
and band toothed gear, or other convenient means, with the rotating
body, engine, machine, or instrument, the speed of which it is desired
to indicate, and the fluid when placed within it rotates with it.
I provide a fixed tube or vessel supported by a suitable frame or
bracket. The lower portion of this tube or vessel passes into the
rotating vessel at its upper end and at or near its axis. From this
fixed tube or vessel a hollow arm projects, and terminates near the
inner circumference of the rotating vessel, but not touching it. In
this hollow arm, at or near its extremity, is an orifice through which
the fluid in the rotating vessel finds its level in the stationary tube or
vessel. The orifice referred to is so placed that when motion is given
to the rotating vessel a portion of the fluid in it is forced in at the
orifice of the stationary tube or vessel, and as the pressure of the fluid
at the orifice is increased by an increase in the speed of rotation the
fluid rises higher in the stationary tube or vessel, and so the height of
the fluid varies according to the speed of rotation given to the rotating
vessel and to the fluid contained in it.
In
In order to enforce and sustain the rotation of the fluid as completely
as possible in conformity with that of the vessel I provide internal
projections connected with or being part of the rotating vessel.
forming these projections I leave a space sufficient so that they may
not interfere with the part which projects from the fixed tube or
vessel.
It will be understood that the projections used for ensuring the
rotation of the liquid with the vessel ensure at the same time the due
pressure of the liquid at the orifice and the equivalent rise of the fluid
in the indicating tube or vessel. The height of the fluid so raised may
represent in conjunction with a scale the number of revolutions (say
per minute) made either by the rotating vessel or by the engine or

page_text: body to which it is connected, and the speed of which it is desired to
know; the scale may also be marked for the fluid to indicate miles or
other measures per hour when the instrument is to be used for indi-
cating the speed of locomotive engines and carriages.
In some cases I use a glass tube as the indicating tube with scale
attached. This tube may be straight, and may rise directly from the
fixed tube or vessel which passes into the rotating vessel, or it may be
bent downwards after it rises from the fixed vessel, but so as to clear
the rotating vessel, and then upwards, the downward run being
sufficiently low to allow of the liquid rising in the final upward run to
the height of the level of the liquid in the rotating vessel when it is at
rest, and so exhibit the starting or zero point from which the liquid
riscs. In some cases the tube may be made partly horizontal, or may
be curved to any required extent. In some cases I use a larger tube
rising from the fixed tube or vessel which passes into the rotating
vessel. This larger tube may be of glass or of metal, in it I use a
float connected with dial and pointer, or other equivalent indicating
means. The rise or fall of the liquid in the tube will in this case
operate the float, and so cause the indication of speed by means of the
pointer on the divided dial. I also employ a float with means attached
to indicate the height of the fluid in the stationary tube or vessel, and
consequently thic speed of rotation of the rotating vessel, or other-
wise, as before explained, of the machine, engine, or body connected
with it.
When it is desired to register or record continuously or otherwise the
rate of motion or number of revolutions (say per minute) made or being
made by the rotating vessel or the machine, engine, or other body
connected with it, in such case I employ a time piece arranged in
connection with my speed indicator, so as to present to a pencil actuated
by the float ruled paper on which a diagram is drawn through the
combined actions of the time piece and the float, which diagram forms
in the usual manner a register of the speed of the rotating vessel, or of
the machine or engine or body the speed of which it is desired to
register. The ruled paper on which the register is made may be placed
on a drum or cylinder of ordinary construction which is turned by thic
time piece, while the pencil is moved by the float in a direction parallel
to the axis of the cylinder, or another well known arrangement may be
used consisting of a dial or disc of paper ruled in concentric circles and

page_text: radiating lines and caused to turn by a time piece, while the pencil in
connection with the float may operate on a line from the circumference
towards the centre of the disc or dial. In this case the radiating ruled
lines will represent time, and the concentric circles will represent the
snood of maiation
connection with the float may operate on a line from the circumference
towards the centre of the disc or dial. In this case the radiating ruled
lines will represent time, and the concentric circles will represent the
speed of rotation.
If preferred the clock movement may be arranged to work the pencil
or it may work a pointer to pierce the paper, the paper being moved by
the float.
The second part of this Invention has for its object the regulating or
governing of the speed of motive power engines, such as steam, water,
and other engines, which are capable of being governed by the opening
and closing of a valve. I employ a vessel formed to contain a suitable
fluid placed on a spindle or in bearings or supports, so that it can be
easily rotated. This vessel is rotated by being placed in connection by
suitable wheels, pulleys, or other convenient mechanical means with
the engine the speed of which is to be regulated or governed by it, and
the fluid when placed within it rotates with it. I provide a fixed tube
or vessel supported by a suitable frame or bracket. The lower end or
portion of this tube or vessel passes into the rotating vessel at its upper
end and at or near its axis. From this fixed tube or vessel a hollow arm
projects towards and terminates near the inner circumference of the
rotating vessel, but not touching it. In this hollow arm at or near its
extremity is an orifice, through which the fluid when put into the
rotating vessel finds its level in the stationary tube or vessel. The
orifice referred to is so placed that when motion is given to the rotating
vessel, a portion of the fluid in it is forced in at the orifice of the
stationary tube or vessel, and as the pressure of the fluid at the orifice
increases by an increase in the speed of rotation the fluid rises higher in
the stationary tube or vessel, and so the height of the fluid varies more
or less according to the speed of rotation given to the rotating vessel and
to the fluid contained in it.
As in the case of my speed indicator I enforce and sustain the
rotation of the fluid as completely as possible in conformity with that of
the vessel by internal projections connected with or being part of the
rotating vessel; in forming these projections I leave a space sufficient
so that they may not interfere with the part which projects from the
fixed tube or vessel.

page_text: It will be understood that as in my speed indicator the projections
used for ensuring the rotation of the liquid with the vessel, ensure at
the same time the due pressure of the liquid at the orifice, and the
equivalent rise of the fluid in the fixed tube or vessel.
In order to operate upon the governing or throttle valve of the engine
by means of the rising or falling of the liquid in the stationary tube or
vessel, I employ a float which I connect with the throttle valve of the
engine by means of toothed wheels, pulleys, and cords, levers, or other
ordinary and convenient mechanical arrangement, so that when in
consequence of an excess of speed in the engine the fluid is raised
above a certain height in the stationary tube or vessel, the consequent
rising of the float partly or entirely closes the valve and shuts off the
steam or other power. When on the other hand the engine does not
run fast enough the fluid in the stationary tube or vessel falls so that
the float is lowered, and thus the valve is opened to permit more steam
or other power to operate, and thus the engine is kept at the desired
rate of speed; the float may be partly balanced by a weight so that the
balance weight will operate on the valve when the float is raised by the
rise of the fluid, while when it falls the excess in the float over that in
the balance weight will operate on the valve, or the valve may be
actuated in one sense by the float being forced up by the fluid, and in
the opposite sense by the weight of the float on the falling of the

page_text: vessel, leaving that part which enters the rotating vessel small, It
desired however the full size of the fixed tube or vessel required for the
float may pass into the rotating vessel.
In order that my said Invention may be most fully understood, and
readily carried into effect, I will proceed to describe the Drawings here-
unto annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 is a view in elevation of ono arrangement of my speed
indicator. The vessel A, which contains the fluid, is shown in section.
The spindle B is fixed to the lower portion of the vessel A, and on it is
a pulley C, by which it may be rotated. The spindle B is pivotted in a
bearing at a. An upper bearing is provided at b, where the upper part
of the frame E projects downwards, and enters into the upper part of
the vessel A. The small hole c serves to admit the air into the vessel
as the fluid is forced out of it upwards into the indicating glass tube F.
The fixed tube or vessel d is attached to the upper or bracket part of
the frame E, to the depending part of which it is screwed. The hollow
arm e projects from the tube d, and has its orifice at f. Through this
orifice the fluid finds its level in the tube d when the vessel A. is at rest.
When motion is given to the vessel A. a portion of the fluid in the vessel
is forced in at the orifice f, and so into the tube d and upwards (according
to the speed of rotation) into the indicating glass tube F. The scale G
may be marked for reading off the result in miles, quantities, revolutions
of the instrument itself, or the equivalent revolutions of any machine or
body, to which it may be connected, and should be divided according to
such circumstances and in accordance with the rise of the fluid attained
by the speed of rotation employed. The length of the indicating tube F
should be suited to the full range of indication desired, or to the highest
speed at which it is intended to rotate the vessel A.
In case of the intended highest speed being accidentally exceeded a
reservoir F¹ may be provided to prevent the overflow of the fluid. The
lower end of the tube F is fitted and cemented into the socket g, which
is screwed into the bracket part of frame E. A band encircles the
head of socket g, and the scale G is attached to it for support.
internal projections (which in this instance are indicated as forming
part of the vessel A) for enforcing and sustaining the rotation of the
fluid in conformity with that of the vessel, and causing it to pass into
Harc

page_text: the orificef. The space i leaves room for the passage of the arm e.
Figure 2 represents Figure 1 in plan at line Z, Z.
Figure 3 represents the arrangement of my speed indicator, in which
a larger fixed tube is employed, and in which larger tube is placed a
float in connection with dial and pointer. This Figure also illustrates a
means by which the rise of the float may communicate its action to
a pencil to effect the recording of such action by diagram upon a paper
covered cylinder moved by clockwork, after the manner of certain
recording instruments already well known. In this Figure the spindle B
of vessel A is shown supported by two bearings a and a placed below it,
and the upper part of vessel A in this case is free, and does not touch
the fixed tube or vessel d, the upper part of which is marked F. The
air has free entrance to the vessel A through the space allowed by the
difference of diameters between the fixed tube d and the hole in the top
of the vessel A. I is the float, which when the vessel A. is rotated is
caused to rise by the forcing of the fluid into the orifice f, as explained
in respect to Figure 1. Float I is connected by cord with pencil slide J,
which acts as a weight to keep the cord under tension, and cause it to
turn the pulley K, which is fast on the spindle upon which the pointer j
is placed. It will thus be seen that the pointer is moved in accordance
with the movements of the float I. It will also be seen that the pencil
slide J owing to its connection with the float I will move in accordance
with it, and trace its rise and fall upon the paper on the cylinder L,
which may be connected with clockwork, so as at the same time to turn
on its axis at any desired rate.
Figure 4 shows a means by which if desired the unequal rise of the
fluid operating upon a float in the manner shown in Figure 3 may be
compensated for ou the scale or dial, so that the pointer may travel
through nearly the same space for every equal number of rotations of
the vessel A, and that consequently the divisions on the dial may be
made equal or nearly so. In this, as in Figure 3, the action of the float
is supposed to be communicated to pulley K, which is fixed to spindle k.
On this spindle is also fixed the cam 1, which when it is turned in the
direction of the arrow by the by the rising of the float will allow the
slide m (to which a small roller is attached and arranged to act on the
cam) to fall. If the cam is accurately formed the slidem will fall through
an equal space for each equal number of revolutions of the vessel A,
and as the rack m' on slide m gears with pinion m² fixed to the pointer

page_text: spindle the movement of the slide m is communicated to the pointer.
n, n, are supports for the dial, and form guides for the slide m, which
has a long opening to allow the spindle k to pass.
Figure 5 shows an arrangement in which the float I is raised above
the vessel A, so that until the vessel A has attained to a given speed of
rotation (during which time the fluid is rising in the fixed tube a) the
float I remains at rest. When bowever the speed of rotation is increased
the float is acted upon until it is raised in the tube or cylinder F. In
this case the float is shown to operate by rack and pinion for indicating
the extent of the motion, the effect of the motion of the float I being
increased by the difference of diameters of the pinion and the drum or
pulley K, to which latter a cord for transmitting the motion to an
indicating or recording apparatus is shown attached. * is a tube,
which may be applied when desired to restrict the height to which the
float may be raised in case of an accidental excessive speed of rotation.
In such case the fluid will escape through the tube n*, and will fall into
the receiver n¹, and so through openings n² will return into the vessel A.
The cylinder or tube F is supported on a portion of a fixed frame E, to
which also the centre tube d is fixed. It will be understood that by
this arrangement, not permitting the rise of the fluid to actuate the
float until a certain speed of rotation has been acquired, the range of
indication or registration may be confined between any ranges of speed,
as may be desired.
In Figure 6 the indicating tube is shown bent downwards after it rises
from the central fixed tube, and then upwards for indicating, so that
the line at Z marks the zero or starting point and level of the fluid in
the vessel A. The internal projections H in this Figure are shown
separate from the vessel A, but are formed on one side of each of two
grooved pierced circular plates o, o¹, made to fit into the vessel A, onc
in the upper portion of the vessel and one in the lower. The ring o²
separates the plates o and o¹ so as to leave room for the passage of the
hollow arm e, which in this case is shown projecting from a circular
disc e¹ which operates to prevent the action of the full length of the
arm against the fluid.

page_text: o, o¹, assist in constraining the fluid to revolve in conformity with the
vessel A and produce its due action at the orifice f.
Figures 9 and 10 show the internal projections H fixed into a centro
boss. One boss with its eight blades is screwed to the upper part of
vessel A, and another p¹ to the lower. Vessel A in these Figures is
somewhat varied in form. The boss p has a hole in its centre to allow
of the passage of the fixed centre tube or vessel which is not indicated
in these Figures. Passages c, c, are provided for the entrance and exit
of air.
Figure 11 serves to illustrate an arrangement of my speed indicator,
by means of which the zero or starting point can be brought into view.
In the indicating tube F is a float I, long enough so that its upper part
is in view when the vessel A is at rest. When motion is given to the
vessel the float will be raised, its upper surface being read against a
scale suitably fixed and graduated. The glass tube F is cemented into
the fixed tube or vessel d.
Figure 12 refers to the second part of my Invention, which has for
its object the regulating or governing the speed of motive-power engines.
A is the vessel which contains the fluid; B, the spindle to which it is
fixed. The spindle B is pivotted at a, and has an upper bearing at a¹.
The means shown for communicating rotation to the vessel A are the
toothed pinion. M fixed to the spindle B, the toothed wheel M¹ on
spindle M², and pulley M³. The supporting frame E is fastened to base
plate E¹, and carries the upper bearing bracket E, the bracket E' for
supporting the central fixed tube or vessel d, and the bracket E' on
which is fixed the cylinder or tube F in which is the float I. The
rack I' which is fixed to float I gears with the toothed sector I³, and is
guided by the upright 1'; lever I' is fast to the same shaft as the
sector 12 so that it will act with it; connecting rod I³ is part of the
means shown for transmitting the movement of the float to the valve of
the steam or other motive engine. On the vessel A. being rotated the
fluid in the vessel passes in at the orifice at the end of the hollow
arme which projects from the centre fixed tube or vessel d. Hare
internal projections such as I have already explained with respect
to the first part of my Invention, and which serve to enforce and sustain
the rotation of the fluid as completely as possible in conformity with
that of the vessel, and to ensure the due pressure of the fluid, at the

page_text: orifice according to the speed of rotation. When sufficient speed of
rotation is given to the vessel A the fluid will rise in tube & until it
reaches the float I, when a further increase of speed is given the float I
will be acted upon, and as the speed increases it will be raised. The
instrument may be so connected with the engine it has.to govern that
when the engine is running at nearly its full speed the float I will be
on the point of being raised so that on any increase in the speed the
valve of the engine will be operated to close through the connections
already explained. As the speed of the engine and consequently of the
vessel A diminishes the float I will fall and the valve of the engine will
be reopened.
Figure 13 also refers to the second part of my Invention and shows
the fixed tube or vessel F required for the float I, placed so that it
passes into the rotating vessel A; in this Figure the float I is shown
assisted by the balance weight J. The two are connected by a cord
passing over a pulley K to which it is attached to prevent slip. The
lever I and connecting rod I° serve, as explained, in respect of the
Figure 12. E represents a bracket or part of a supporting frame. It
is shown supporting the central cylinder or vessel F rising from the
central tube d.
Figures 14, 15, 16, 17, 18, and 19, represent various forms of pro-
jecting arms, and orifices suited both for the first part and for the second
part of my Invention. In each Figure d is the central fixed tube or vessel;
e, the hollow arm; and f, the orifice. Figures 18 and 19 illustrate the
disc e¹ referred to in the description of Figure 6, in which Figure it is
also shown. In Figures 18 and 19 a means is shown of reversing the
orifice from one side of the hollow arm to the other, in order that
when desired the vessel containing the fluid may be rotated in either
direction. The reversing of the orifice is obtained by the cylindrical
valve g, which fits freely in the tube 7. This valve takes its position on
one side or the other of the hollow in the arm e, according to the
direction in which the fluid is moved. The pins s form stops for the
valve q.
In Figures 20 and 21 d is the central tube; e, the projecting arm;
and f, the orifice. These last Figures represent a small size arm and
orifice, such as may be conveniently used in carrying out that arrange-
ment of my speed indicator, in which I use a small bore indicating glass
tube. The sizes of the fixed centre tubes, the projecting arms and

page_text: orifices, will depend upon the size of the instrument and the use for
which it is destined.
The disc e', Figures 18 and 19, may be used or not as preferred, in
conjunction with any of the forms of projecting arms e shown.
In indicating the similar parts in the various Figures I have
endeavoured to use similar letters of reference in order to render it
unnecessary to repeat the explanation of such parts.
My rotating vessels whether intended for my speed indicators or
speed regulators or governors may be filled with the fluid, or may some-
times be only partially filled. It will be found advantageous generally
to fill them when they serve for my speed indicators, more especially
when they are arranged to indicate from zero.
In arranging the Drawings which illustrate my Invention I have sup-
posed mercury to be the fluid used.
I have shown my speed indicators with open top indicating glass
tubes, so that the upward rise of the fluid may not be impeded by the
air in the tube, but when preferred, as in the case of a shorter and more
equally graduated scale being desired, these tubes may be closed at the
top and the scale suitably graduated. In such cases a reservoir for
air of suitable size may be placed at the top of the tube, so that the
risc of the fluid will be checked to the desired extent by the resistance
of the air in the tube and reservoir. As errors in the indications may
arise under this arrangement owing to the expansion and contraction of
the air, according to temperature, a cock or other means may be pro-
vided to equilize, when desired, the pressure of the air in the tube
and reservoir to that of the outer air.
The indicator tube when closed at the end may be placed horizontally
or at an angle, and may be straight or spiral, the scale being graduated
suitably.
In place of using a glass indicating tube with closed end in which
the position of the fluid is read by a scale, an ordinary pressure gauge
may in some cases be employed, attached to the central tube or vessel d,
so as to be operated upon by air compressed by the force imparted to
the fluid according to the speed of rotation. In such case the dial
plate of the pressure gauge should be suitably graduated for speed.
More than one orifice ƒ may be used when desired, connected with the
centre fixed tube or vessel d.

page_text: Having thus described the nature of my said Invention and the
manner of performing the same, I would have it understood that I do not
claim the mechanical parts separately, but I claim in respect of the first
part of my Invention,-
First. The construction and use of speed indicators with a rotating
vessel, arranged to contain and carry round with it mercury or other
liquid, in such manner that the liquid is forced into an orifice supported
within the rotating vessel, and through a channel leading from the
orifice to a tube or vessel, in which by virtue of the pressure of the
liquid at the orifice, increasing with the speed of rotation of the vessel,
it serves to indicate or operates apparatus which will indicate the speed
of the rotating vessel or other body or thing connected with it, sub-
stantially as herein described.
Second. The combinations of parts constituting respectively the speed
indicators, substantially as described.
I claim in respect of the second part of my Invention,-—
First. The construction and use of speed regulators or govenors with
a rotating vessel, arranged to contain and carry round with it mercury
or other liquid, in such manner that the liquid is forced into a stationary
orifice, supported within the rotating vessel, and through a channel
leading from the orifice to a tube or vessel, in which by virtue of thic
pressure of the liquid at the orifice increasing with the speed of rotation
of the vessel it operates through suitable mechanical connections upon
the throttle valve or equivalent part of the engine to be controlled,
substantially as described.
Second. The combinations of parts constituting respectively the speed
regulators or governors, substantially as described.
In witness whereof, I, the said James Murdoch Napier, have
hereunto set my hand and seal, this Twenty-seventh day of
May, in the year of our Lord One thousand eight hundred and
seventy-six.