Year: 1889

page_text: Date of Application, 27th Aug., 1889-Accepted, 29th Mar., 1890
COMPLETE SPECIFICATION.
The form of the rheobathometer may vary, but its external surface must be so
arranged around a straight line, which forms the vertical axis of the instrument, that
every part of its surface is symmetrical with reference to that axis and also with
reference to a plane surface passing at right angles through the middle of the
axis.
The rheobathometer has an average specific gravity smaller than water, when the
sinker arranged inside the buoy is detached from the instrument, and it has an
average specific gravity greater than water when the sinker is attached to the
instrument. The weight of the different parts of the instrument are so arranged,
that its center of gravity with or without the sinker lies in the vertical axis and
considerably below the center of its length.
To fit the instrument for the several purposes for which it is designed, the outside
shell is divided into two or more compartments, one of which is to contain liquid or
fluid, which is to give the necessary buoyancy to the instrument, while the other
or others contain the sinker for causing the rheobathometer to descend to the bottom,
when attached to it. I also provide a releaser which is to cause the sinker to be
detached from the instrument when it strikes the bottom or when the device which
I have termed a timer and which can be arranged to actuate the releaser after the
lapse of a predetermined time, and before the rheobathometer reaches the bottom;
and an indicator, a device which indicates the place where, and the time when the
rheobathometer returns to the surface of the water.
The shell of the rheobathometer is cylindrical in form with ogyval ends and
has cylinders of small diameter protruding from the ogy val ends. This shell is con-
structed of two parts, the upper part A the extreme lower end of which is shown in

page_text: figure 1, while the upper or main portion thereof is shown in figure 1º, and the lower
part B shown in figure 1, the two parts being joined on line HH, the joint being
made by means of a cylindrical ring r This ring is secured to one section by pins
or equivalent devices, and is provided with screw threads which engage internal
threads formed on the adjacent end of the other section. At the top of the upper
part the shell is perforated to admit the introduction of the tube t. The shell is
divided into two unequal compartments Q and Q¹, by the diaphragm d, d, which is
secured to the shell a short distance above the joint H, H. The longth of the upper
part or section is determined by the amount of buoyancy required, and the lower part
or section B is made simply of sufficient length to contain the timer, releaser and
other devices required for operating the instrument.
In the center of the upper compartment, the small tube t, is fastened, being passed
through the hole left for that purpose, at the upper apex of the shell. The lower end
of the tube t, t rests on the diaphragm d and at that point is perforated at v, to admit
communication between the liquids contained in the main body of the compartment Q¹
and those in the tube t, t. The opening at the highest point of part or section A
serves for the escape of air, while the compartment is being filled with naphtha by
pouring it into the open upper end of tube t. After the compartiment Q is full
of the liquid, and the air has all ascended, the opening is closed by screw tap s.
The portion of the tube t, t, protruding above the apex of the ogyvie shell is
reinforced by a ring N screwed to it; and at two opposite points of the circumference
of this ring, indentations n, n are made with which engages the device employed
for supporting the instrument to lower it into the water as will hereinafter be
described.
To this ring N, the tube c¹, is fitted and held in position by friction, so that it may
readily be attached or detached. This tube is made of very thin metal; at its upper
end, a cap e² in the form of a truncated cone, open at its upper end, and perforated
at h², h², on its sides, is placed. Near the base of the cap c², wire netting w is
secured thereto. The cap is fitted to the tube so as to be held by friction.
A short distance above the lower end of the tube c¹, the diaphragm d2 of the form
of an inverted cone, is fixed to the sides of the tube c'. Immediately above the
diaphragm the sides of the tube care provided with small holes h, h. Larger
holes , h, are made in the sides of the cylinder immediately below the diaphragm d².
To the center of the upper surface of the diaphragın da stiff wire is attached,
which at its upper end, carries a small cup c³. The upper part of the tube c¹ contains
a tube g of very thin glass, closed at its upper end, and open at the lower; its outside
diameter being a little smaller than the inside diameter of the tube c'. During the
time the rheobathometer is descending and ascending, the tube c', is filled with water,
except the glass tube g which is filled with naphtha, the buoyancy of which operates
to lift the glass tube against the wire netting w. Within the glass tube is a globule
of potassium u which latter is suspended by a fine wire v¹ from the top of the
glass tube.
In the lower compartment Q, Q, of the instrument, cylinder E is placed. This
cylinder is connected at its lower end with the shell of the rheobathometer and its
upper end is covered with a cap i, which is provided with openings h³, see Fig. 4;
the cap i carries the standards m, m, which support the shafts a, a, of the sheaves S.
Near the upper end of the cylinder recesses are cut on its inside see Fig. 5
ribs q, q, being left to guide the piston P when it reaches that part of the
cylinder.
The cylinder E is divided into two parts by a diaphragm d¹, placed below the
middle of the cylinder E; the space above the diaphragm d' contains the piston P
to the lower face of which is secured the piston rod 1, the latter extending downwardly
through the diaphragm d', and into the tube c, c; both the piston and the opening
in the diaphragm d' through which the piston rod passes are provided with hydraulic
packing for the reception of which grooves in both piston and diaphragm are repre-
sented in Fig. 1. To the lower end of the piston rod la conical ring p is fastened.
The piston Phas a small hole 7° bored vertically through its center and another small

page_text: hole h is bored horizontally through the upper end of the piston rod. These holes
serve to allow the water in the upper end of the cylinder E to enter the space between
At the middle of the
the piston and diaphragm, when the piston P is being raised.
upper surface of the piston a stirrup s is fastened, to which two strings or fine chains
of equal length, to wit, u', and u² are attached. These strings pass up vertically to a
central opening in cap i, thence onto and around the sheaves S, down the open
space Q between the cylinder E and shell of the buoy. The strings are fastened to
opposite points of ring-shaped weight R, which fits loosely in the annular space.
The piston P is further provided with two vertical holes which are closed by
valves, when the piston is drawn upward, and which readily open when the piston
is pushed downward in the cylinder.
The cylinder E is provided with holes * immediately below the diaphragm d',
to admit of the escape of air from the cylinder E when the instrument is immersed in
water.
The shell of the rheobathometer is perforated for the same purpose by holes h,
below the diaphragm d, and by holes . In the lower part of the space of
section B are three vertical plates j, j which are radially arranged and attached to
the shell and serve as supports for annular rings of metal M which are employed
when it is desired to reduce the buoyancy of the instrument.
A curved springs is fastened to the cap and clamps the two strings u³, u², when the
free ends of the spring are in the position shown in figure 3, but when small knob k²
is pushed in so as to bring its outer end even with the surface of the shell, the small
wedge w², attached to the rod connected with the knob pushes the two branches of the
spring apart, and allows the strings to move.
The sinker S3 is placed in the lowest portion of cylinder E. The body of the
sinker is cylindrical in cross section its diameter being slightly less than that of the
cylinder E. The sinker is provided with a central hole formed through its vertical
axis to admit the tube to pass freely through it. Its lower surface is shaped to the
same form as the ogy val upper end of the rheobathometer and its top surface is of
exactly the same form. At two points of its circumference, the sinker is provided
with vertical bars 63 which are flush with the surface of the sinker and project a
short distance above the upper outer edge thereof, and at their extreme upper ends,
carry hooks pointing inward.
A series of vertical grooves are cut into the surface of the sinker, as shown in
figure 11, four of which, to wit g³, serve to secure the proper position of the sinker,
when it is placed in the instrument by means of the inwardly projecting guides p*
secured to the inner surface of the cylinder E fitting within the vertical grooves in
the sinker and guide it vertically, when it is released, and for the same purpose, two
vertical ribs are formed on the inner surfaces of the cylinder E and fit into the
vertical grooves g² formed in the outer surface of the sinker.
The four vertical grooves g³ in the circumference of the sinker are so arranged
that the sinker, when detached from and leaving the instrument, will clear the
four short pins p', which are attached to the inside of the cylinder E near its lower
end.
On the top of the sinker rests the follower F, a cylindrical piece of metal having
a central perforation of the same diameter, as the corresponding hole in the sinker.
The outside diameter of the follower is also the same as that of the sinker. Its
bottom surface is congruent with the upper surface of the sinker and its upper
surface has the shape of an inverted cone.
The circumference of the follower is provided with two vertical grooves q³ which
are cut at opposite points, and these grooves fit over the vertical bars y³ attached to
the inside of the cylinder E. These grooves and bars serve to secure the proper
position of the follower F, and to guide it in its descent after the sinker has been
discharged; two square notches ns, n³ cut in the circumference of the follower F
serve to allow the passage of the hooks 3 through the follower F without touching
it, when the sinker is discharged. There are other vertical grooves p cut on the
circumference of the follower, which allow it to pass by the pins p*, p*, without

page_text: touching. Above these grooves p³ stirrups of wire t² are fastened on the top of the
follower, so arranged that they rest on the pins p₁, after the follower has descended
and that the lower surface of it is flush with the surface of the shell of the
rheobathometer.
The hooks attached to the sinker rest, while the instrument is descending
through the water, on two other hooks placed at the ends of the vertical arms of
bent levers L. The bent levers L with their vertical and horizontal arms, have
their pivots on short shafts y, and these latter are supported by brackets attached
to the sides of the cylinder E. Light springs attached to the sides of the
cylinders, serve to press the vertical arms of the bent levers L outwardly and against
the inner surface of the cylinder E.
.
The tube when not pushed upward by striking the bottom rests on the cross
bars 18 attached to the sides of the cylinder E the upper end of the tube being
provided with a conical ring 2 the lower end of which forms an annular seat which
rests on the cross bars 68 as shown in figure 7. The cross bar has a centrally
located circular opening of a diameter slightly larger than that of the tube so that
the latter can move freely up and down in it. The conical ring 722 engages the
horizontal arms of the bent lever L when the tube c¹ is raised sufficiently, and serves
to lift the arms and disengage the vertical hooked arms from the hooked bars on the
sinker. That part of the tube c below the sinker, when the latter is attached to the
instrument, has externally the same form as the portion of the tube c¹ protruding
from the upper ogyvic end of the buoy. The weight of the tube must be sufficient
to prevent its being raised by the impact of the water on its lower end while the
instrument is descending towards the bottom.
In the operation of the device the upper compartment Q' of the buoy is filled with
naphtha; while the cylinder E is filled with water of the same specific gravity as that
of the water in which the instrument is to be used.
That part of the tube c¹ above the diaphragm d2 including the glass tube in
which a globule of potassium is suspended, are filled with naphtha. To prevent the
naphtha escaping from tube y through the small openings in the side of tube c¹,
these holes are filled up with some substance, such as gelatine, which is insoluble in
naphtha, but soluble in water. The glass tube 9 is fastened to the wire gauze w, by
the same kind of substance.
The piston timer consisting of the weight R, sheaves S, S, strings u¹, u², as herein-
before described is shown as having been set to allow the piston to make a full stroke
before the weight R causes the sinker to be detached. If it were desirable that the
sinker should be detached in a shorter time the piston would have to be set at some
point between the position shown in the drawing and the cap i, i of the cylinder.
The length of time in which the piston makes a full stroke is ascertained by
experiment and when it is desired to actuate the releaser in a shorter space of time
the spring is opened which releases the cords u¹ and u² and allows the piston P to
ascend the distance it would move in the interval between the time required by the
piston to make a full stroke, and the time in which it is desired that the releaser shall
be actuated.
The weight R is held from descending and raising the piston P and piston rod 7 by
the strings u¹, u² being clamped by the spring (see figure 3), until the instrument
is being immersed, when the small knob is pushed in and the wedge w² driven
between the ends of the spring, releases the strings and allows the piston P to be
pulled up toward the top of the cylinder E by the weight R.
9
The filling of the tube c' with naphtha and the insertion of the glass tube with
its suspended globule of potassium, may be performed some time before the instrument
is to be used. For this purpose, tube c¹ and its cap c², with the glass tube glued
to the wire gauze w and containing the globule of potassium are submerged in the
same vessel which is filled with naphtha until both are full and until all the air has
escaped from them. The cap c² is placed in the cylinder c', while both are held
under the surface of the naphtha. The holes in the cap are then temporarily stopped
up to prevent evaporation of the naphtha.

page_text: The indicator so prepared, may be kept separate from the instrument until the
latter is to be used. When the instrument is to be used, the tube c' is placed on
the top of the rheobathometer, and the holes in the cap c² are opened.
The instrument is then suspended by inserting the pointed ends of the pincers P
shown in figure 8, into the indentations n, n, in ring N, which is fastened to the
upper end of the tube t. The pincers are pressed against the ring by the operator
pulling on string a, which is attached to the upper end of the pincers; the string u
being at the same time held loosely in the hands of the operator. The rheobatho-
meter is then gradually lowered into the water after the knob ² has first been
pushed in, to release the strings. The moment at which the timer is set going by
the pushing in of the knob k² must be noted. As the instrument is being immersed
below the surface of the water the air from the lower part of the buoy will escape
through holes, 1, 1, and the whole buoy below the diaphragm d, will fill with
water. As the instrument is still further lowered, the naphtha from tube t will also
escape and will be replaced by water. After the instrument has been entirely
submerged, the naphtha inside cylinder c₁ will escape through holes h², except what
is contained in the glass tube g. The whole cylinder c', with the exception of the
glass tube, but including the small cap c², will then be filled with water.
;
The rheobathometer is then allowed to depart toward the bottom by the operator
pulling string, and letting loose string the jaws of the pincers will open and
discharge the instrument. The time when the instrument is released from the pincers
must be noted.
The rheobathometer as soon as released from the pincers will descend through the
water and its velocity will be gradually increasing; but the increments of velocity
will rapidly decrease, as the resistance of the water increases with the square of the
velocity. So that after a few seconds the instrument may be considered as having
acquired a constant motion. For instruments travelling at a slow velocity no correc-
tion need be made on account of the gradual increase of velocity. For rheobatho-
meters constructed to travel at a great speed, the correction can readily be made.
When the rheobathometer arrives at the bottom, tube e in striking will be retarded
by the resistance of the material of which the bottom is composed, and the
rheobathometer continuing its travel, the horizontal arms of the bent levers will strike
the conical piece or ring 72 at the top of tube ct and release the sinker. This cuts
the connection between the sinker and the remainder of the instrument and the gravity
of the sinker which has been the impelling force ceases to act, the buoyancy of the
instrument will cause it to reascend towards the surface; the sinker being of course
left at the bottom.
The piston of the timer has meanwhile been kept moving and will continue to do so
until it reaches its highest position; but it can in nowise interfere with the further
ascent of the instrument. If the piston of the timer is set so as to reach the upper
end of its stroke before the instrument reaches the bottom the conical ring p attached
to the lower end of the piston rod will turn the bent levers L and release the sinker.
If the rate at which the instrument of a certain form travels under the impulse has
been ascertained by experiment and the time elapsing between the moment when the
instrument was discharged and when it reappears on the surface has been observed
the depth of water can readily be ascertained. If the velocity due to a given weight
of sinker has by experiment been found as being and the velocity due to a certain
buoyancy has been ascertained as being and if the time in seconds during which
the instrument was submerged is T the depth d is d
=
ལྤ° ལྕ°
(2.1 + 2.2)
T.
If the force impelling the instrument to descend is equal to the force causing it
to ascend which can he readily arranged by making the weight of the sinker (in
water) exactly double the weight in water required to overcome the buoyancy of
the instrument without the sinker, the time required for the descent and ascent of the
Τυ
instrument will be equal and the depth d =
provided that the form of the
2
instrument is symmetrical and offers the same resistance to motion in both directions.

page_text: It is absolutely necessary to make these forces equal when the velocities due to the
action of certain weights are to be ascertained by experiments which are instituted in
deep water whose depth is known.
There will be certain disturbing causes which affect the uniformity of motion, as
for instance, the changes in the density of water at different depths or from difference
in temperature of the water, also the compressibility of naphtha or similar liquid with
which the upper compartment Q is filled and of the material of which the instrument
is constructed; but it would be easy to show that proper corrections can readily be
made, and that the instrument itself may be used for ascertaining the necessary co-
efficients to be used for making such corrections. If the piston of the timer is set at
such an elevation in the cylinder E that it will complete its stroke before the rheo-
bathometer reaches the bottom, the velocity of the annular weight R which will be
accelerated as soon as the piston reaches the lower edge of the recesses cut in the
sides of the cylinder and the conical piece p attached to the lower end of the piston
rod will strike the horizontal arms of the bent levers with sufficient force to actuate
then and cause the discharge of the sinker and the rheobathometer to ascend to the
surface.
The rate of travel of the rheobathometer under the impulse of a certain weight or
force being known and the total time consumed in its ascent and descent having been
observed, the depth below the surface to which the instrument has penetrated, can be
calculated in the same way as in the case where the instrument descended to the
bottom. It will not be necessary, for this purpose, that the timer should act like a
regular time piece unless it is desirable that the instrument should descend to a
certain precise depth which for the purpose above indicated will rarely be
required.
When the instrument arrives at the surface of the water on its return from the
depth to which it had been penetrated, its upper part will rise above the surface more
or less according to its buoyancy. By this time the gelatine, which has been used for
sealing the small holes and for attaching the glass tube y in the tube c', will have
dissolved in the water and the glass tube will, from the buoyancy of the naphtha con-
tained in it float on the water surrounding it. But when the tube c' rises above the
surface of the water, the water contained in that tube will escape through the small
holes h, and the glass vessel with its globule of potassium will follow downward.
When the potassium reaches the water, contained in the small cup it will suddenly
ignite, break the glass vessel, and set the naphtha, which had been contained in the
glass vessel, on fire. The smoke caused by the burning of the naphtha, in day time,
and the light emitted from it, at night, will indicate the place where, and the time
when, the instrument has arrived at the surface.
The use of the indicator of course is only required when the instrument is expected
to be under the surface of the water for a considerable time.
The indicator, may however, also be used to great advantage, if soundings are to
be taken by a ship travelling at full speed. For such soundings, a cheaper form of
rheobathometer would be used, and no effort made to recover the instrument.
The time elapsing between the discharge and reappearance of the instrument as
stated gives the depth, and if the location of the points at which the indicator enters
the water and reappears therefrom can be measured from some fixed point, a line
drawn between these points, will give the average direction and the distance between
these points, the average velocity of the currents prevailing between the surface and
the point to which the instrument had descended. If the total time elapsing between
the discharge and reappearance of the instrument is called T; the rate of vertical
travel of the instrument (arranged for equal forces and equal resistances in both
directions) v, and the distance between the point of discharge and reappearance of the
instrument, the depth is d
=
Tv
2
and the average velocity of current
T
The bearing of the line ioining the two points on the surface whare the instrument

page_text: Having now particularly described and ascertained the nature of my said inven-
tion and in what manner the same is to be performed I declare that what I
claim is :-
1st. A rheobathometer constructed to present an equal resistance to its passage
through the water in the direction of its axis both in ascending and descending, and
provided with a detachable sinker and sinker holding and releasing devices the latter
being located within the shell of the rheobathometer.
2nd. A rheobathometer the shell or casing of which is formed to present an equal
resistance to its passage through water in the direction of its axis, both in ascending
and descending through the water, said shell being divided into two compartments,
one to contain liquid which serves to give buoyancy to the shell and the other to
contain the devices for operating the rheobathometer, substantially as set forth.
3rd. The combination with a shell or casing divided into compartments, of a tube
open at the upper end and descending to the bottom of one compartment set apart for
containing the liquid used for giving buoyancy to the rheobathometer for the purpose
of equalizing the inside and outside pressure, the said tube being perforated at its
bottom.
4th. The combination with a shell or casing divided into compartments, of a sinker
secured to the shell and so shaped that when in place the outside surface of the instru-
ment at its lower end is of the same form as the upper end.
5th. The combination with a shell or casing divided into compartments, and a
sinker so arranged that when in place the outside surface of the instrument at its
lower end is of the same form as the upper end, of a follower for restoring the
symmetrical form of the surface of the buoy, when the sinker has been discharged.
6th. In a rheobathometer, the combination with shell or casing a timer and a
sinker, of a releaser for discharging the sinker both by striking bottom and by the
timer.
7th. The combination with a rheobathometer, of a timer, by means of which the
sinker may be discharged after a certain lapse of time, for the purpose heretofore
stated.
8th. The combination with a rheobathometer, of the indicator for, indicating by
light or smoke, or by both light and smoke, the reappearance of the rheobathometer at
the surface.
+ 1000
CRUIKSHANK & FAIRWEATHER,
62, Saint Vincent Street, Glasgow, Agents.