IMPROVEMENTS IN SHIPS' LOGS.”
Year: 1873

page_text: LETTERS PATENT to Halfoord Sigfrid Cederholm and Carl Peterson,
of 3, Lime Terrace, New Charlton, in the County of Kent, for
the Invention of "IMPROVEMENTS IN SHIPS' LOGS.”
the Invention of IMPROVEMENTS IN SHIPS' LOGs.”
"
COMPLETE SPECIFICATION filed by the said Halfoord Sigfrid Cederholm
and Carl Peterson at the Office of the Commissioners of Patents,
with their Petition and Declaration, on the 17th April 1873,
pursuant to the 9th Section of the Patent Law Amendment
Act, 1852.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, HALFOORD
SIGFRID CEDERHOLM and CARL PETERSON, of 3, Lime Terrace, New
Charlton, in the County of Kent, send greeting.
WHEREAS we are in possession for an Invention for "IMPROVEMENTS
IN SHIPS' LOGS," and have petitioned Her Majesty to grant unto us, our
executors, administrators, and assigns, Her Royal Letters Patent for
the same, and have made solemn Declaration that we are the true
and first Inventors thereof.
NOW KNOW YE, that we, the said Halfoord Sigfrid Cederholm and
Carl Peterson, do hereby declare that the following Complete Specifi-
cation, under our hands and seals, fully describes and ascertains the

page_text: The log consists of a wooden cylinder A, Fig. 1, three inches in
diameter, at the ends of which are attached a propeller B and a' wheel-
work C, the axle of the propeller having a crank at its end so as to form
an excentrical motion, and it works a connecting rod. D, fixed upon a.
balance E; this balance acts upon two others, which are connected by
means of two copper wires, and communicates the motion to the wheel-
work through a lever F and a ratchet wheel G. This wheelwork consists
of five wheels, three of which are for indicating the knots, as on ordinary
ship logs, and two others for regulating the motion, if required, and

page_text: working by friction, and can thus be adjusted by moving a screw H,
Fig. 2, which enables the main wheel I to revolve slower and faster
according to the position it has been set to the centre.
.
The log is fixed to the vessel in the following way:-A tube of iron or
copper is placed vertically about two feet from the keel, on fore or after
deck, with a hole through the bottom corresponding with the tube, for
the purpose of allowing the water to pass to a level; the length of the
tube depends upon the depth of the ship. It is protected from injury by
a cover of iron or wood. The log has at the upper end a ring K, Fig. 5,
adjustable so that when let down it can be shifted, in order to get the
propeller in working order, and when not wanted it can be lifted up four
inches, by which the propeller becomes inactive, and is kept within the
ship by means of a spring L, Fig. 5, which acts against the inner side of
the tube, and becomes hereby absolutely safe from damage.
We do not confine ourselves to any special form of log, but this we.
have here shewn and described in detail is what we prefer, as we have
found it to be the most efficient for the purpose required from an
extended series of trials and experiments.
And having now described the nature of our said Invention, and in
what manner the same is to be performed, we declare that we claim,―
First. The construction and employment of logs or speed indicators,
which can be fixed inside, and passing through the hulls of ships or
vessels, substantially as described and shewn.
Secondly. We claim any speed indicators worked by electricity, being
connected with the main log for the purposes herein-before described in
this Specification, and as shewn on the accompanying Drawing or any
mere modification thereof.
In witness whereof, we, the said Halfoord Sigfrid Cederholm
and Carl Peterson, have hereunto set our hands and seals, this
Seventeenth day of April, in the year of our Lord One thousand
night hundred and cawants the
HALFOORD SIGFRID CEDERHOLM. (L.S.)
CARL PETERSON.
(L.S.)