AN IMPROVED LOG OR INSTRUMENT FOR MEASURING THE SPEED OF SHIPS AND THE VELOCITY OF STREAMS OF WATER
Year: 1861

page_text: LETTERS PATENT to John Boulby, of Whitby, in the County of York,
Land Surveyor, for the Invention of "AN IMPROVED LOG OR INSTRUMENT
FOR MEASURING THE SPEED OF SHIPS AND THE VELOCITY OF STREAMS OF
WATER."
Sealed the 23rd July 1861, and dated the 28th January 1861.
PROVISIONAL SPECIFICATION left by the said John Boulby at the
Office of the Commissioners of Patents, with his Petition, on the 28th
January 1861.
I, JOHN BOULBY, of Whitby, in the County of York, Land Surveyor, do
hereby declare the nature of the said Invention for "AN IMPROVED LOG OB
INSTRUMENT FOR MEASURING THE SPEED OF SHIPS AND THE VELOCITY OF STREAMS OF
WATER," to be as follows:-
The improved instrument consists of an axis or spindle having vanes or blades
fixed thereon, similar to a screw propeller, forming together a rotator, which will
revolve when drawn through the water by the action of the water on the vanes.
The rapidity of the revolution depends upon the rate at which the rotator is
drawn. The hinder end of the spindle passes into a conical metal case or box; the
spindle enters at the apex of the cone and passes in the direction of its axis.
By a suitable arrangement of teethed wheels, the spindle when made to
revolve by the action of the water on the vanes, communicates motion to an
index at the hinder end or base of the cone. The base of the cone forms a
dial, for the purpose of determining the velocity and speed of a ship, or the
distance it has proceeded in a given time. The instrument may be fixed at
the side of the ship, care being taken to place it so far from the ship as to be

page_text: clear of the water disturbed by the ship's motion, and immersed to such a
depth that it will be constantly below the surface of the water, notwithstanding
the heeling, pitching, or rolling of the ship; and if so used or fixed, the instru-
ment is supported by two slight bars or rods, which, when in use, project
from the ship. The front end of the spindle passes through a hole in the end
of one of the bars, in which it revolves freely, and the conical box is fixed to
the end of the other bar. The instrument may also be towed astern of the
ship by a cord, so as to he used in the ordinary manner. In this case I use a
flat metal bar or keel, to one end of which an upright rod is fixed, the other
end of the upright rod being fixed to the metal box or case; another upright
rod is fixed to the other end of the keel. There is a hole in the upper end of
the last-mentioned rod in which the front end of the spindle revolves. The use
of the keel is to prevent the box revolving with the rotator.
When it is
required to stop the rotator I use a light metal cap or circular plate, fixed
through the centro upon the cord holding the log, which, upon being disen-
gaged, descends by gravity, and the action of the water upon or in front of the
instrument, and by impeding the action of the water upon the rotator causes
it to cease revolving, or the rotator may be liberated and stopped by the
following arrangement:-A spring is fixed on the last-mentioned upright rod,
having a catch or detent at one end which takes into a ratchet wheel on the
A cord is
front end of the spindle and prevents the revolution of the rotator.
attached to the detent, and is so arranged that when the instrument is towed
through the water by the last-mentioned cord, the detent is drawn out of the
ratchet wheel and the rotator is free to revolve. There is another cord attached
to the upright rod in which the spindle revolves. When the instrument is
towed by the last-mentioned cord, the detent is brought by the spring into
the ratchet wheel, and the revolutions of the rotator stopped, and when the last-
mentioned cord is slacked, and the instrument towed by the cord attached to
the detent, the rotator is liberated and free to revolve.
For the purpose of measuring the velocity of a stream of water, the instru-
ment, supported in a suitable frame, is immersed, the front end of the spindle
pointing towards the direction from which the stream flows. The number of
revolutions, as indicated by the index on the dial in a given time, shews the
velocity of the stream. Instead of vanes or blades on the spindle, I sometimes
use a screw, the thread of which takes about one turn; this is acted on by the
water in the same manner as the vanes or blades, and causes the rotator to
revolve.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said John Boulby in the Great Seal Patent Office on the 27th
July 1861.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN
BOULBY, of Whitby, in the County of York, Land Surveyor, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-eighth day of January, in the year
of
our Lord One thousand eight hundred and sixty-one, in the twenty-fourth year
of Her reign, did, for Herself, Her heirs and successors, give and grant
unto me, the said John Boulby, Her special licence that I, the said John
Boulby, my executors, administrators, and assigns, or such others as I,
the said John Boulby, my executors, administrators, and assigns, should
at any time agree with, and no others, from time to time and at all times
thereafter 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 Invention for "AN IM-
PROVED LOG OR INSTRUMENT FOR MEASURING THE SPEED OF SHIPS AND THE
VELOCITY OF STREAMS OF WATER," upon the condition (amongst others) that
I, the said John Boulby, my executors or administrators, by an instrument
in writing under my, or their, or one of their hands and seals, should par-
ticularly 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 John Boulby, do hereby declare the
nature of my said Invention, and in what manner the same is to be per-
formed, to be particularly described and ascertained in and by the following.
statement, reference being had to the Drawings aunexed hereto, and to the
letters and numbers thereon, that is to say :-
One mode by which my said Invention may be performed is represented by
Figure A. No. 1 is a conical box of copper or other metal furnished with a
flat metal bar or keel 2, one end of which is attached to the base end of the-
cone. A spindle S passes into the box in the direction of the axis of the cone,.
through a water-tight collar 4 in the apex of the same, and revolves in another
bearing within the box at 5, and in another in the cone at 6. A loop of metal 7,.
affixed to the end of the keel, enables a rope to be attached for towing the:
machine through the water. To the spindle are attached curved vanes or
blades 8, 8, similar to those of a screw propeller, by means of which the spindle

page_text: is made to revolve whenever the box is drawn through the water, or is fixed in
a stream or current of water running from the apex to the base of the cone.
The box, when drawn through the water, is prevented from revolving by the
keel. A pinion wheel 9 is fixed upon that extremity of the spindle which is
within the box, by which pinion the spindle, when revolving by the action of
the water upon the vanes, is made by a suitable arrangement of toothed wheel-
work as shewn in the Diagram, to communicate motion to an index 10, work-
ing in a dial 11, by which means the velocity of a current of water, the speed
of a ship, or the distance it has proceeded in a given time may be readily ascer-
tained and shewn, and which dial is fixed at the base of the conical box, and is
protected from the water by means of a piece of thick glass 12, which is kept
in its place by screwing the metal ring 18 tightly up to the box, and between
which glass and the shoulder 14 an india-rubber washer 15 is placed. Instead.
of vanes or blades upon the spindle, a screw may be used, the thread of which
must have a suitable turn. This will be acted upon in the same way as the
vanes or blades, and in like manner will cause the spindle to revolve.
Another and a preferable mode by which my said Invention may be per-
formed is represented by Figure C. No. 1 is a conical box of copper or other
metal, connected with a ring 2 by means of a swivel 3, and having curved
vanes or blades 4, 4, fixed to its outside, which vanes cause the box to revolve
whenever it is drawn through the water by the ring, or is allowed to revolve
in a stream or current of water running from the apex to the base of the cone.
A rod 5 is fixed within the box in the direction of the axis of the cone by
means of bars 6, 6, attached to the sides of the box, or by some similar method,
so that it may revolve along with the box. A pinion wheel 7 is fixed upon the
rod and revolves with it. A weight 8 is hung loosely upon the rod by means
of one or more circular holes through which the rod passes, and thus affords a
fixed point for the axis of the toothed wheel 9, which works into the pinion 7.
Upon the axis of the wheel 9 is a pinion 10, which works into two toothed
wheels 11 and 12; the rod passes through the axis of the wheel 11, which
axis is a hollow tube carrying an index hand 18. The wheel 12 is fixed to and
revolves with the dial 14, both of which work loosely upon the tubular axis of
wheel 11. The wheel 11 has one tooth more than the wheel 12. The dial
can be seen through, and is protected from the water by a piece of glass fixed
in the base of the cone, similar to that shewn in Figure A. The action of the
machine is as follows:-When the box revolves as before described, the weight
8 always remaining perpendicular, motion is given to the wheels 11 and 12 by
the pinion 10, but as the wheel 11 which carries the index has one tooth more
than the wheel 12 which is attached to the dial, the latter revolves more slowly

page_text: than the former, and the difference between their respective motions, which will
indicate the number of revolutions made by the box, will be shown by the figure
on the dial to which the index hand points, and the number of revolutions of
the box will shew the distance through which the machine when used as a
ship's log has been drawn through the water.
In the above arrangement the different parts may be so proportioned as that
the index hand will revolve once round the dial for every ten miles that the
machine has been drawn through the water.
Figure B is an end view of the machine shewn in Figure C. In Figure B,
1 is the dial, 2 the index, and 3 shews the position of the weight. If it is
desired to indicate a greater number of miles travelled, the arrangement shewn
in Figure D may be adopted. In this arrangement a pinion 15 is fixed upon
the tubular axis of wheel 11, and revolves with it in front of the dial. This
pinion works into the wheel 16, which revolves upon an axis 17 attached to
the dial. One of the radii of the wheel 16 (see Figure E, No. 18) acts as an
index upon the small dial 19, Figure E, and shews the number of revolutions
made by the index 13 upon the dial 14, Figures D and E. When the machine
is used as a ship's log it is desirable that it should be made as nearly as pos-
sible of the same specific gravity as sea water, and to float with the axis of
the cone as nearly as possible in a horizontal position. The line by which it is
towed should be long enough to keep it clear of the ship's wake, and a weight
sufficient to sink it attached to the line a little in front of the machine.
What I claim as my Invention is, the use of the keel as and for the purpose
described in the first mode by which my Invention may be performed and the
placing of the conical box behind the vanes, the mode of indicating the number
of revolutions of the vanes, the form of the machine, and the combination of
its various parts, as respectively shewn in Figure A.
I also claim the combination of the various parts of the machine and form
of the machine as respectively shewn in the Figures B, C, D, and E, and the
application of such combination to the measuring of the speed of ships and the
velocity of streams of water.
In witness whereof, I, the said John Boulby, have hereunto set my
hand and seal, this Twenty-sixth day of July, in the year of our Lord
One thousand eight hundred and sixty-one.
JOHN BOULBY. (Ls.)