IMPROVEMENTS IN SHIPS' LOGS, OR APPARATUS FOR ASCERTAINING THE SPEED OF SHIPS
Year: 1863

page_text: LETTERS PATENT to Frederick Bullock, Rear-Admiral, of No. 16,
Richmond Terrace, Gravesend, in the County of Kent, for the Inven-
tion of "IMPROVEMENTS IN SHIPS' LOGS, OR APPARATUS FOR ASCERTAINING
THE SPEED OF SHIPS."
Sealed the 31st March 1864, and dated the 22nd October 1863.
PROVISIONAL SPECIFICATION left by the said Frederick Bullock at the
Office of the Commissioners of Patents, with his Petition, on the
22nd October 1863.
I, FREDERICK BULLOCK, Rear-Admiral, of No. 16, Richmond Terrace,
Gravesend, in the County of Kent, do hereby declare the nature of the
Invention for "IMPROVEMENTS IN SHIPS' LOGS, OR APPARATUS FOR ASCERTAINING
THE SPEED OF SHIPS," to be as follows:-
This Invention has for its object improvements in ships' logs, or apparatus
for ascertaining the speed of ships. For this purpose I employ a float, which
by means of a line I tow behind the ship; this line I tie to or otherwise
connect with a spring balance or other weighing instrument, which may be
of ordinary construction, and which will accurately measure the strain on the
line; and as this strain will vary according to the speed at which the ship is
.dragging the float through the water, when the amount of strain is known
the speed can at once be ascertained from a table prepared for the purpose,
either from experiment or otherwise. If desired, the spring balance or
weighing apparatus may be graduated or arranged so as to indicate at once
the speed of the ship.

page_text: SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Frederick Bullock in the Great Seal Patent Office on the
22nd April 1864.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, FREDERICK
BULLOCK, Rear-Admiral, of No. 16, Richmond Terrace, Gravesend, in the
County of Kent, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the Twenty-second day of October, in the year of our Lord
One thousand eight hundred and sixty-three, in the twenty-seventh year of
Her reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Frederick Bullock, Her special licence that I, the said Frederick
Bullock, my executors, administrators, and assigns, or such others as I, the
said Frederick Bullock, 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, exer-
cise, and vend, within the United Kingdom of Great Britain and Ireland, the
Channel Islands, and Isle of Man, an Invention for "IMPROVEMENTS IN SHIPS'
LOGS, OR APPARATUS FOR ASCERTAINING THE SPEED OF SHIPS," upon the condition
(amongst others) that I, the said Frederick Bullock, my executors or adminis-
trators, 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 Frederick Bullock, do hereby declare
the nature of the 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 thereof, that is to say :-
This Invention has for its object improvements in ships' logs, or apparatus
for ascertaining the speed of ships. For this purpose I employ a float, which
by means of a line I tow behind the ship; this line I tie to or otherwise
connect with a spring balance or other weighing instrument, which may be of
ordinary construction, and which will accurately measure the strain on the
line; and as this strain will vary according to the speed at which the ship is
dragging the float through the water, when the amount of strain is known
the speed can at once be ascertained from a table prepared for the purpose,
either from experiment or otherwise. If desired, the spring balance or

page_text: And in order that my said Invention may be most fully understood and
readily carried into effect, I will proceed to describe the Drawings bereunto
annexed.
DESCRIPTION OF THE DRAWINGS.
Figure 1 shows the stern of a ship with apparatus applied thereto for
carrying out my Invention in the manner I prefer. a is a rod fixed at the
stern of the ship and supported by the bracket b, on it is the ring or traveller c,
having the line d attached to it, which also passes around a sheave e at the lower
end of the rod a, by means of this line the traveller can be caused to slide up
or down along. the rod a. Attached to the traveller there is the block f, and
round it the log line g, which should be of considerable length (say, 50 yards,)
passes from the log h to the indicator i. The log his conveniently a metal
cylinder closed at the ends, it is towed behind the ship. The log line g is
kept nearly parallel with the surface of the water by adjusting the block f to
a distance of only about 3 or 4 feet from the water's surface. The indicator i,
which is fixed within the ship, and has the inner end of the tow line attached
to it, is a spring balance of ordinary but accurate construction; it, as will be
seen, weighs the strain on the log line. The proper graduation of the indicator
dial is ascertained by experiment in the first place, the positions of the hand
or pointer when the ship is running at known speeds being observed afterwards,
other indicators may be made from the one so graduated by experiment. k is
a guy rope for staying the lower end of the rod a.
In witness whereof, I, the said Frederick Bullock, have hereunto set
my hand and seal, this Twenty-second day of April, in the year of our
Lord One thousand eight hundred and sixty-four.
FRED. BULLOCK. (L.S.)
Vice-Admiral.