Improvements in Electric Ship Log Apparatus.
Year: 1897

page_text: Improvements in Electric Ship Log Apparatus.
A communication from abroad by WARREN HENRY MCCURDY, of Pier 19, North
Delaware Avenue, Philadelphia, Pennsylvania, United States of America,
Master Mariner.
I, ALFRED GEORGE BROOKES, of 55 and 56, Chancery Lane, in the County of
London, Chartered Patent Agent, do hereby declare the nature of this invention
to be as follows:-
The invention has for its object to provide a ship's log of novel construction
capable of closing an electric circuit after the ship has travelled a predetermined -
distance, the electrical impulse actuating a registering mechanism if desired, to
make a distance record on a suitable tape, and stamp the time, the difference of
time indicated between one and the next time stamp record indicating the time
required to travel a certain distance.
The electrical impulse may also actuate a visual registering mechanism, which
will indicate the number of miles travelled by the ship.
The mechanism in which I embody my invention comprises a ship's log having
a chamber for the reception of an insulating plug, and open at its end for the
reception of an electric cable, the latter being provided with one or more strength-
giving wires, and with electric wires, all of the wires being wrapped together within
an insulating protector, and arranged to co-operate with a push button, and suitable
actuating mechanism for the latter.
Also my invention embraces the special electric cable mentioned, this cable
consisting of a compact bunch of electric wires, and one or more strength-giving
wires, bound together by a protecting covering, and the strength-giving wire or
wires being firmly secured to the log.
The log will preferably comprise four general divisions, viz.:-a frame-work
containing the push button actuating mechanism, a shell enclosing this frame-
work, and the latter being preferably packed water-tight within the shell, and
terminal portions at either end of the shell, the forward portion receiving an
insulating plug and containing the electric cable, strength-giving wires, etcetera,
above mentioned, and the rear terminal portion being provided preferably with
ball bearing connections having a rotator secured thereto, this rotator being
adapted to drag considerably behind the log.
The rotator connections within the rear terminal of the log and the push button
actuating mechanism may be connected by means of two discs mounted on the
ends of the respective shafts of said two sets of mechanism, these discs being
brought together face to face, and secured by suitable fastening means, as pins,
symmetrically arranged therein.
The push button actuating mechanism may be variously constructed; I prefer,
however, to have a worm mounted on the main shaft within the log, this worm

page_text: meshing with a worm gear and through a train of gearing actuating a step cam,
the latter bearing loosely against the end of a push rod, on the other end of which
rod is the push button.
The push rod is mounted in suitable bearings, which may be one of the heads
of the mechanism supporting frame within the log, and is surrounded by a piece
of tubing, this tubing being connected to the said head and to a collar on the rod,
thereby forming a water-tight joint.
This feature of my invention, however, is not absolutely essential, inasmuch as
I contemplate connecting the terminal wires of the electric circuit by means of a
tube filled with mercury, against which tube the push button will operate, thereby
cutting off the mercury intermittingly to cause the required pulsations in the
registering mechanism on board of the ship.
When this mercury contact device is not used, I prefer to mount the log
mechanism in a frame independent of the shell, this frame having opposite heads
packed water-tight in the shell and a shaft extending outwardly from one of said
heads to be engaged and driven by the driving shaft from the rotator.
When the log is placed overboard in the water, the rotator, as it is drawn in
the water, will turn and rotate the driving shaft causing it to rotate the worm shart
and turn the train of gearing above described, the cam thereof acting on the push
rod to slide it back and forth in its enclosing tube, and thereby operate the push
button to make and break the electric circuit through the wires of the cable.
This cam may be rotated once for every one tenth of a mile or any other desired
distance, and at each time that the circuit is completed an electric impulse is sent
through the circuit to do work.
A recording time stamp is preferably placed in the chart-room of the ship,
having an inking ribbon, and co-operating with this ribbon is a strip or ribbon of
paper which may be unwound from any suitable reel and wound again onto any
suitable receiving reel.
Suitable feed rolls are provided to intermittingly feed the paper immediately
after closing the circuit in the ship's log, a suitable spring or weight acting
through a train of gearing to rotate the feed rolls, as commonly practised in auto-
matic electric registers.
The stamp is in the electric circuit, and it is operated every time its magnet is
energized in usual manner, and it may be arranged to stamp on either side of the
paper ribbon.
The circuit also contains a registering mechanism, preferably mounted in the
saloon in view of the passengers, consisting of a train of gearing and dials over
which hands travel, one of said dials representing units, the following ones, tens,
hundreds, thousands and tens of thousands, so that by moving the gearing at the
first dial by or through a suitable magnet, the said dials may be moved step by
step, and from them may be readily seen the number of miles that the ship has
travelled on its voyage.
This ribbon of paper may be stamped with any imprint to show the time of day
or night and the number of miles.
The stamp may also mark the record 10 of a mile and by counting off ten
stamps and taking the difference of their time, the time consumed in travelling
any one mile of the journey may be accurately ascertained.
The cable will be mounted on a suitable reel having electrical connections so
that it may be rotated to give off or take up the cable as required, and yet the
cable will always be in circuit.
While I prefer to cast the ship's log into the water, yet it is within my invention
to fix the log on ship-board to be actuated by the rotator.
My invention is an improvement in electric ship's logs, and in the manner of
using the same, including novel provision for preventing the entrance of water to
the log and to the electric terminals, and also including the operation thereby of
a distant time stamp record, and also of two sets of registering mechanisms and

page_text: independent electrical circuits connected therewith; my invention including also
various details of novelty, including an automatic switch, showing the circuit
connections of my improved registering system.
I employ a device for maintaining the log in proper trailing position.
My log may be made with a shell composed of three parts, screwed firmly
together, and having suitable joints the particular placement of the joints being
chosen to accommodate the insertion and removal of the contained parts.
A rotator, such as is customarily used in connection with logs of this variety,
will be connected by a cable secured to an eye-piece or the like this eye piece may
be held by a set screw on a threaded end of the main shaft of the log, ball bearings
being provided, in order to reduce the friction thereof.
The shaft at its forward end has a crank or disc extending transversely thereof,
and engaged by pins extending through perforations in a disc or plate adapted to
fit against the disc of the main shaft, and carried by a worm shaft, provided with
a worm meshing with a worm gear which, in turn, by intermediate gearing, drives
a small cam and a large cam to reciprocate make and break plungers.
The disc may terminate co-extensively with such a part of the case, and the
make and break mechanism terminate with such other part of the case, that the log
is readily removable in parts so that when the one part is screwed off from the
rest of the log, the driving shaft and its parts are at once removed from the gears
and worm shaft; and the fore and middle parts may be unscrewed from each
other, leaving all of the driving mechanism within the latter.
In order that the gearing may be readily removed from the log, I prefer to
mount the same in a frame, this frame comprising heads grooved externally to
receive packing to make water tight joints between the heads and the interior of
the part.
The middle part of the shell contains a plug of wood or other insulating
material, for the reception of the circuit wires, there being say four of these wires
or say optionally simply two wires making an ordinary single circuit, and I prefer
to strengthen the cable containing these wires, by including therewith strength
giving wires preferably secured to the plug by suitable screws in order to give
the cable tensile strength, to prevent it from pulling apart under the constant
strain of dragging the log through the water.
In practice, I prefer to employ two circuits, it being understood, however, that
my invention of course includes the employment, if desired, of only one circuit.
In my preferred construction, I provide means for quickly detaching the log
from the cable for the purpose of repairs and inspection.
A short section of cable may be encased in a thin sheath of brass, copper, or
other suitable material, provided with a flange at one end, by which it is held by
a shoulder of the fore end screwed onto the middle part of the log, a washer or
packing being interposed.
On the opposite end of the sheath is soldered or screwed a tapered annulus
having an end shoulder against which a tapered screw nut abuts tightly, to
engage the threaded end of a socket end, a packing ring being compressed between
the latter and the annulus.
The socket end is preferably projected to receive the projecting end of the socket,
and is gradually tapered along the cable, so as to offer the slightest resistance in
passing through the water.
The conducting wires protrude from the cable and enter the sockets in the end
of the section attached to the fore end, being pressed into intimate contact with
the adjacent ends of the section of conducting wires carried thereby, the end of
the tube section being preferably filled with cement, provided with said sockets,
although other means of making this contact union may be used.
When, therefore, it is required to remove the log, all that is necessary is to reel
in the cable, unscrew the connecting nut and pull the cable apart at its joint;

page_text: another log may then be quickly substituted or the old one may be at once con-
veniently repaired and quickly replaced.
One constant aim of invention in electric logs is to make it impossible for water
to get at the contacts and thereby short-circuit the log and render it useless for
registering purposes.
The packed heads as well as the plug and other features referred to are improve-
ments in this direction, but, nevertheless, under the rapid movement of the log
and the unremitting pressure, of the water, some of the latter will inevitably seep
into the log; if water should come in at the tail-end of the log, where there are
necessarily moving joints, and there get past the rear head I prevent its access to
the contact spring which is pressed into contact with the circuit wire by a plunger
by surrounding the latter with a piece of rubber tubing preferably bound by wire
to a collar on the plunger and to a shoulder of the head, the plunger being pre-
ferably insulated at its ends, so as to minimize the tendency thereof to short circuit
the apparatus under the influence of the moisture.
The plunger is acted upon by a suitable spring retractor which holds it in
contact with the cam, the latter having an abrupt shoulder, in order to give
a sharp break of the circuit, and the plunger having a roll adjustably screwed on
to its end to reduce the friction of the plunger against the cam.
It may practically be impossible, however, absolutely to keep out all moisture,
notwithstanding the close joints of the shell, the packed heads of the log, and the
other features already described, and, therefore, I prefer to enclose the wire
terminals in the ends of a strong rubber tube, the intermediate portion of the latter
being filled with mercury the inturned ends of the tube being embedded or sealed
in a cavity filled with cement.
The plungers may have blunt ends which are brought to bear intermittingly on
the middle portion of the tube, thereby compressing the walls thereof and breaking
the column of mercury and electric current, as desired, without any interference
of surrounding water.
I do not claim the inventing of a mercury column make-and-break, my inven-
tion residing in the application thereof to an electric log in such manner that even
if, in practice, the log should get full of water, the electric action thereof would
be comparatively unaffected.
Having described the details of construction of my log, I will now set forth that
part of my invention which pertains to its use in connection with my new system.
It will be supposed that the vessel is provided with a dynamo and with a
complement of batteries although any other sources of electric energy may be
substituted.
A suitable number say four terminals or binding posts at each end respectively
of two independent registering mechanisms are respectively in circuit with the
dynamo and battery, a wire connecting from a post to the dynamo, another wire
connecting thence to an electro magnet of an automatic switch, the circuit pro-
ceeding thence by wire to a reel containing an out wire and a return wire in the
cable, and reaching the opposite post by a wire.
The wiring of the battery circuit may be by wires from a post to the battery, to
a spring contact arm, from an armature of the switch of the log's cable between
the reel and another post.
I arrange the cable so that it passes inwardly to the axis of the reel, and that
the respective wires are thence carried to the ends of the axis, where certain wires
have their terminals connected to contact rings on the reel, which receive brushes,
the said terminals having contact with spring brushes respectively.
I do not limit myself to the system of wiring above indicated, as any arrange-
ment may be employed comprising two circuits and any means to switch from one
to another, the switching means in and of themselves not being a feature of my
invention, the latter residing rather in the novel application thereof, and in the
system as herein described, whereby two circuits are utilized and are capable of
being used automatically one or the other, or both, if desired.

page_text: In the switch indicated, the armature is or may be held by a spring under a
tendency to move out of contact with the electro magnets and into contact with
an arm, adjusting screws being provided for a purpose.
As the dynamo is started its current energizes the electro magnets thereby
pulling over the armature against the tension of its spring, breaking the battery
circuit and establishing the dynamo circuit; the result is that the battery is saved
from exhaustion and the registering mechanism is operated by the circuit including
the terminals, the other and inactive battery circuit remaining ready instantly
to resume its work the moment that for any reason a current ceases to energize
the electro magnets, the spring at such moment shifting the armature into contact
with the arm to make the battery circuit.
The two circuits may, if desired, be employed to operate one and the same
registering device, but I prefer to have the circuit including the usually operating
current of the vessel, (supposed in the present instance to be a dynamo circuit),
connected to operate the register, the latter indicating, for instance, nautical miles
or other considerable distances, and to have the other circuit connected to operate
the register indicating, for instance, tenths of miles or other short distances.
By means of this provision, I am enabled to take the speed accurately in tenths
of miles when passing through fogs in dangerous localities, nearing a shore,
entering a harbour, etc., and yet not be obliged to register more than miles on the
general run of the course, day by day.
In some instances, however, it may be desirable to throw both registers into
operation for a time, and therefore, I provide any suitable means therefor, as set
screw, by means of which the arm may be clamped down against the armature to
complete the battery circuit at the same time that the dynamo circuit is active.
The main purpose, however, of my system, as above outlined, is to prevent the
loss of mileage and of registered data, in case the dynamo should break down
or need repairing, or the batteries should run out without its being noticed, it
might be at night; my invention insuring the reliability of the log, inasmuch as
if one circuit breaks down it is automatically cut out and the other circuit thrown
in; and upon again starting the dynamo, for instance, the log will be automati-
cally shifted at once out of circuit with the battery and into circuit with the
dynamo.
Of course the two plungers are continuously operated in the log continually
compressing and releasing the mercury or other contact, but, inasmuch as only one
circuit, presumably, is active, one of these plungers accomplishes no work; it
will be understood that one of the plungers works much more rapidly than the
other, it being intended herein to shew them as proportioned to indicate miles and
tenths of miles respectively, although any other relative speed may be had, as
desired, simply by changing the gearing.
In order to provide a convenient record which may be read at a convenient
place on the ship, as, for instance in the saloon by the passengers, or in the chart
room or elsewhere by the ship's officers, giving exact time and distance, I provide
a recording time stamp in one or in both of the circuits already alluded to.
A suitable recording time stamp may be used having an inking ribbon and co-
operating with this ribbon is a ribbon of paper which may be unwound from any
suitable reel and wound again onto any suitable receiving reel, being passed
between the rolls which act to feed the strip, these being actuated intermittingly
immediately after closing the circuit, by a usual spring or weight and gearing but
inasmuch as the details of construction of the time stamp do not enter into my
invention, I shall not further elaborate the description of parts commonly under-
stood.
The magnets of the stamp are energized by the current passing through the
wire in usual manner, so that every time the log sends an impulse over the
wire, the time stamp will make a record on one side or the other of the strip of
paper, for instance, where the imprint shows the dial of a clock with an hour and

page_text: minute hand, the position of the imprint of the hands being constantly changing
as the hand indicating portions of the clock train are revolved by the clock
mechanism contained in the time stamp, said mechanism being well known; and
also showing the year, month, and day, and whether the division of the day is A.M.
or P.M., it being within the contemplation of my invention also to provide a number-
ing stamp if desired, to also stamp the mile numbers on the strip, although the
latter may be readily estimated from the successive stamps.
While I prefer to cast the ship's log into the water, yet I wish it understood that
the log mechanism may be fixed on shipboard and actuated by its rotator, if
desired.
I have not herein described the internal construction of the registering mechan-
isms inasmuch as these are well known devices and consist of successive trains of
gears, the dials indicating units, tens, hundreds, etc.
For the most efficient use, a log should not follow in the wake of the ship, that
is, it should not be in the dead water but should follow on the lee side, and,
accordingly, I have provided a device for insuring the proper trailing position of
the log, consisting in a leader box which may be and preferably is made in two
parts hinged together and provided with a clasp or latch to unite with a lock and
having a passage with a conical forward opening centrally therethrough to receive
a conical shoulder of a tubular jacket such as a piece of brass or other metal tubing
permanently secured on the cable so as to permit limited flexure thereof but
prevent sharp bending which would tend to break and injure the cable, the leader
being secured behind the ship by means of small chains or wire ropes and lines,
leading from the respective sides of the ship through rings or guides.
From the above description, it will be evident that by slacking on one line and
pulling in on another line, the leader and therefore the cable held thereby will be
shifted from the lower side to the upper side and, vice versa, by pulling on the one
line and slacking on the other line the cable will be shifted back again, so that the
log may be readily made to follow the vessel on one side or the other, or, if desired,
by simply adjusting the lines, it may be made to follow midships.
Dated the 8th day of Iun 1807
Improvements in Electric Ship Log Apparatus.
A communication from abroad by WARREN HENRY MCCURDY, of Pier 19, North
Delaware Avenue, Philadelphia, Pennsylvania, United States of America,
Master Mariner.
3
I, ALFRED GEORGE BROOKES, of 55 and 56, Chancery Lane, in the County of
London, Chartered Patent Agent, do hereby declare the nature of this invention 40
and in what manner the same is to be performed, to be particularly described and
ascertained in and by the following statement:-
My present invention relates to improvements in apparatus of the kind set forth
in the Specification of my Patent No. 29813 of December 28th 1896.
One serious objection to an electric log is that no record is made thereby when 4
the dynamo or other source of electricity stops, and inasmuch as the dynamo is

page_text: liable to be stopped temporarily at any time, or the batteries are liable to run out
without its being noticed, it may be at night, the reliability of the log is greatly
impaired.
In carrying out this invention there are provided therefore, two independent
sources of electric energy, one of which is normally inactive, and these are con-
nected by an automatic switch, so that in case the dynamo should break down or
need repairing, no mileage would be lost, the log being automatically out of circuit
with the dynamo and put in circuit with a battery or other source of electric
current; and, upon again starting the dynamo, the log would be automatically
shifted at once out of circuit with the battery and into circuit with the dynamo.
A further provision relates to registering speed for special purposes, as, for
instance, when entering a harbour, nearing land, etcetera; ordinarily it is sufficient
to register miles or even tens of miles, but under certain circumstances, such as I
have indicated for example, it is desirable to be much more definite and to register
shorter distances, as tenths of miles.
Accordingly my invention comprehends means for shifting the log into one or
another circuit to accomplish this purpose, thereby getting the speed in one
denomination normally and in another denomination when desired, the power or
current in either case being cut-off and saved from the moment that the other
circuit is brought into registering action.
Provision is also made for readily removing my improved log from its cable
for repairs, for instance, without distubing the latter or its connected mechanism;
improvements are also made in the internal mechanism of the log, including means
rendering of little damage the accidental entrance of water into the log, said
entrance having been heretofore disastrous in preventing proper electrical action.
The various details of my invention will be more definitely understood in the
course of the following description, reference being had to the accompanying
drawings, illustrative thereof.
In the drawings, Fig. 1 is a diagrammatic view including an automatic switch
showing the circuit connections of my improved registering system;
Fig. 2 is a central longitudinal section of my improved log and a portion of its
cable;
Fig. 3 is a detail in side elevation of a contact plunger;
Fig. 4 is a perspective view, parts being broken away, showing one of the
circuit interrupting mechanisms.
Fig. 5 is a side elevation, showing the operating mechanism of the log in its
frame, removed from the casing or shell;
Fig. 6 is a plan view, showing a device which I employ for maintaining the log
in proper trailing position.
For the purposes of illustration in describing my invention, it will be supposed
that the vessel is provided with a dynamo A and with a complement of batteries B,
although any other sources of electric energy may be substituted.
Four terminals or binding posts a, a, b, b¹, are respectively in circuit with the
dynamo A and battery B, a wire connecting from post a to the dynamo, a wire 1ª
connecting thence to an electro-magnet c of an automatic switch C, the circuit
proceeding thence by a wire 1b to a reel 1) containing an out wire 1° and a return
wire 1d in the cable E and reaching the post a by a wire 1.
to
The wiring of the battery circuit is illustrated by wires 2 from post
battery B, 2 to a spring contact arm c', 2b from an armature of the switch C,
2c, 2d of the logs cable E, and 2° between the reel and post b¹.
I do not limit myself to the system of wiring above indicated, as any arrange-
ment may be employed comprising two circuits and any means to switch from one
to another, the switching means in and of themselves not being a feature of my
invention, the latter residing rather in the novel application thereof, and in the
system as herein described, whereby two circuits are utilized and are capable of
being used automatically one or the other, or both, if desired.

page_text: In the switch herein shown, the armature c3 is held by a spring under a
tendency to move out of contact with the electro magnets c and into contact with
an arm c, adjusting screws c, c, being provided for a purpose presently to be
described.
As the dynamo A is started, its current energises the electro magnets c, thereby
pulling over the armature c, against the tension of its spring ³, breaking the
battery circuit and establishing the dynamo circuit; the result is that the battery
is saved from exhaustion and the registering mechanism is operated by the circuit
including the terminals a, a', the other and inactive battery circuit remaining
ready however instantly to resume its work the moment that for any reason a 1
current ceases to energize the electro-magnets, the spring at such moment
shifting the armature into contact with arm c¹ to make the battery circuit.
The two circuits may, if desired, be employed to operate one and the same
registering device, but I prefer to have the circuit including the usually operating
current of the vessel (supposed in the present instance to be a dynamo-circuit)
connected to operate a register F indicating, for instance, nautical miles or other
considerable distance and to have the other circuit connected to operate a register G
indicating for instance, tenths of miles or other short distance.
By means of this provision, I am enabled to take the speed accurately in tenths
of miles when passing through fogs in dangerous localities, nearing a shore,
entering a harbour, etcetera; and yet not be obliged to register more than miles
on the general run of the course, day by day.
In some instances, however, it may be desirable to throw both registers into
operation for a time, and therefore I provide any suitable means therefor, as the
set screw c³, by means of which the arm c¹ may be clamped down against the
armature to complete the battery circuit at the same time that the dynamo
circuit is active.
Referring now to Fig. 2, which shows my improved log in longitudinal section,
I designates a shell, containing watertight packed heads I, I¹, make and break
mechanism, shaft k, its end piece k¹ for connection to the rotator, not shown, and a
plug h.
As specified in my before-mentioned patent, it is essential that sea-water shall
not get inside of the log and into contact with the electric terminals, because if it
does the circuit is thereby completed through the water and all accuracy of
registering is destroyed.
It is practically impossible, however, to absolutely keep out all moisture, not-
withstanding the close joints of the shell and the packed heads of my log, and
therefore I have enclosed the wire terminals in the ends of a strong rubber tube h¹,
see Fig. 4, the intermediate portion of the latter being filled with mercury h²,
and have embedded or sealed the inturned ends of the tube in a cavity filled
with cement h³.
A blunt plunger is brought to bear intermittingly on the middle portion of the
tube, whereby compressing the walls thereof and breaking the column of mercury
and electric current, as desired, without any interference of surrounding water,
that may seep into the log.
I do not claim the invention of a mercury column make-and-break, my inven-
tion residing in the application thereof to an electric log in such manner that
even if, in practice, the log should get full of water, the electric action thereof
would be comparatively unaffected.
A cam, driven by worm and pinion connection from the shaft k, bears on a
roll 3 carried in the bifurcated end of a plunger, see Fig. 3, which operates
through the head I and carries a blunt point to compress the terminal tube h
of the dynamo-circuit, a spring in a pocket bearing against a shoulder k³
on the plunger to hold the latter in engagement with its cam.
A small pinion 10 is indicated by dotted lines, turning with the cam k² to drive
a larger gear 2 and cam k¹³, the latter bearing on a roll 14, see Fig. 4, of a

page_text: spring overhanging the terminal tube h¹, said spring having a blunt lip k16
to compress the tube and thereby break the electric current of the battery circuit.
Any other operating mechanism may be employed, I having shown my present
improvements as applied in connection with the log of my aforesaid patent for
convenience merely.
It is evident that the cam ³, supposed to rotate once every tenth of a mile,
and the cam 3, supposed to rotate once every mile, will make and break their
respective columns of mercury at every rotation, but the effective one only will
be registered for the reason that the automatic switch C maintains one circuit
broken or cut out, as before explained.
It is necessary that the union between the log and its cable should be exceedingly
strong and durable, permitting limited flexure and offering a minimum hindrance
in dragging through the water, and it is at the same time desirable that the log
may be capable of quick removal for repairs and inspection.
Accordingly I encase a short section e of the cable in a thin sheath M of brass,
copper or other suitable material, provided with a flange m at one end by which
it is held by a cap m¹ screwed onto the end of the log at m², a washer or packing m³
being interposed.
On the opposite end of the sheath M is soldered or screwed a tapered annulus m
having an end shoulder m³ against which a tapered screw nut m abuts tightly to
engage the threaded end m² of a socket end m³, a packing ring m³ being com-
pressed between the latter and the annulus m⭑.
The socket end is preferably projected, as shown, to receive the projecting end of
section e and is gradually tapered as shown at m¹0 along the cable E so as to offer
the slightest resistance in passing through the water.
The four conducting wires protrude from the main cable and enter sockets in
the end of the section c, being pressed into intimate contact with the adjacent ends
of the sections of conducting wires carried thereby, the end of the tube section
being preferably filled with cement m¹² and provided with sockets.
When, therefore, it is required to remove the log, all that is necessary is to reel
in the cable, unscrew the nut me and pull the cable apart at its joint; another log
may then be quickly substituted or the old one may at once be conveniently
repaired and quickly replaced.
While I prefer to cast the ship's log into the water, yet I wish it understood
that the log mechanism may be fixed on ship board and actuated by its rotator,
if desired.
I have not herein described the internal construction of 'the registering
mechanisms F, G, in as much as these are well-known devices and consist of
successive trains of gears, the dials indicating units, tens, hundreds, etcetera.
For the most efficient use, a log should not follow in the wake of the ship, that
is, it should not be in the dead water but should follow on the lee side, and,
accordingly, I have provided a device as shown in Fig. 6, for insuring the proper
trailing position of the log, consisting in a leader box P, herein shown as made in
two parts p, p, hinged and provided with a clasp or latch p³ to unite with a
lock p, and having a passage with a conical forward opening p³ centrally there-
through to receive a conical shoulder p6 of a tubular jacket p, herein shown as a
piece of brass, or other metal, tubing permanently secured on the cable E so as
to permit limited flexure thereof but prevent sharp bending which would tend to
break and injure the cable, the leader P being secured behind the ship by means
of small chains or wire ropes 28, and lines 7º, 710, leading from the respective
sides of the ship through rings or guides p
From the above description, it will be evident that by slacking on the line p
and pulling in on the line plo, the leader and therefore the cable held thereby will
be shifted from the one side as shown in Fig. 6 to the other side thereof, and, vice
versa, by pulling on the line p³ and slacking on the line 210 the cable will be
shifted back again, so that the log may be readily made to follow the vessel on one

page_text: side or the other, or, if desired, by simply adjusting the lines, it may be made to
follow midships.
Various changes and substitutions in details of construction and arrangement
may be resorted to without departing from the spirit and scope of my invention.
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 :-
1. In an electric ship log apparatus or a ship's log registering system, two
independent sources of electrical energy, registering mechanism, circuits from said
two sources of energy to the log and said registering mechanism, and means to
automatically switch one of said sources of energy into circuit when the other of
said sources of energy ceases to supply a working current, substantially as and for
the purpose set forth.
2. In an electric ship log apparatus or a ship's log registering system, a log,
electric circuits, two independent registers, one being normally active and one
normally inactive, and means to put one or both of said registers in circuit with
said log as desired, substantially as and for the purpose set forth.
3. In an electric ship log apparatus or a ship's log registering system, a log,
two registering mechanisms, electrical connections therefor, a main source of
energy, normally in circuit, an auxiliary source of energy normally out of circuit,
and means to automatically put said auxiliary source of energy in circuit when
said main source breaks down or ceases to supply a given current, substantially
as and for the purpose set forth.
4. An electric ship log apparatus provided with wiring making two independent
circuits, substantially as and for the purpose set forth.
5. In an electric ship log apparatus, means to prevent the entrance of water
therein, and additional means to prevent the access of moisture to the terminal
wires, said means including a rubber tube connecting the said terminals, sealed
thereabout at its ends, and filled with a liquid conductor, substantially as and for
the purpose set forth.
6. An electric ship log apparatus, provided with four electric wires making two
independent circuits, the ends of said wires being sealed in the ends of rubber
tubes and intermediately connected by mercury within the tubes, substantially as
and for the purpose set forth.
7. In an electric ship log apparatus two independent electric circuits, and two
make and break mechanisms, one for each circuit, substantially as and for the
purpose set forth.
8. In an electric ship log apparatus, two independent electric circuits, and two
make and break mechanisms, one for each circuit, one of said mechanisms being
operated faster than the other, substantially as and for the purpose set forth.
9. In an electric ship log apparatus, a terminal comprising a rubber tube filled
with mercury sealed against entrance of moisture, a break device to compress said
tube, and means to operate the same, said device being provided with a blunt
edge, engaging the tube, substantially as and for the purpose set forth.
10. In an electric ship log apparatus, a make-and-break mechanism, comprising
a plunger, a spring retractor, a friction roll carried on said plunger, and an
actuating cam, said roll engaging said cam and said retractor maintaining said
engagement, substantially as and for the purpose set forth.
11. In an electric ship log apparatus, a make-and-break mechanism comprising
a plunger, a bearing therefor, a roll journalled in one end of said plunger, a cam 5
engaging said roll, and means to actuate the same, substantially as and for the
purpose set forth.
12. The combination with an electric ship log apparatus, and its cable, of a
section extending beyond the log and capable of limited flexure, said section
having a shouldered annulus secured on its outer end, and a screw nut abutting i
against said shoulder, and the adjacent end of the cable having a long tapered

page_text: socket end to offer least resistance in the water threaded to engage said screw nut
opposite said annulus, substantially as and for the purpose set forth.
13. The combination with an electric ship log apparatus and its cable, of an
intermediate section, comprising a flexible sheath, a cap at one end to fasten the
same to the log, and a joint connection at the other end to join the section to said
cable, said connection comprising a tapered and threaded socket end, a shouldered
annulus, and a screw nut, substantially as and for the purpose set forth.
14. In combination with an electric ship log apparatus, a tubular section con-
taining conducting wires for connection to the log, and a cable also provided with
conducting wires, the latter wires projecting from and beyond their cable, and the
adjacent end of said section being provided with sockets containing and in which
are exposed the ends of its wires, said sockets receiving the said projecting wires
of the cable when the latter is coupled to said section, substantially as and for the
purpose set forth.
15. In an electric ship log apparatus, a device for governing the trailing position
of the log, comprising a leader secured behind the vessel and adapted to retain the
cable of the log, and having means connecting the same with the vessel whereby
the cable may be shifted laterally relatively to the vessel, as desired, substantially
as and for the purpose set forth.
16. In an electric ship log apparatus, a device for governing the trailing position
of the log, comprising a leader secured behind the vessel and adapted to retain
the cable of the log, said cable having a flexible jacket secured thereto and pro-
vided with a shoulder to engage the forward end of said leader, said leader having
means connecting the same with the vessel whereby the cable may be shifted
laterally relatively to the vessel, as desired, substantially as and for the purpose set.
forth.