AN INSTRUMENT OR INSTRUMENTS, TO BE USED JOINTLY OR SEPERATELY, FOR ASCER- TAINING A SHIP'S WAY AT SEA, AND ASSISTING IN DETERMINING THE LONGITUDE
Year: 1813

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, WILLIAM
POPE, of the City of Bristol, Perfumer, send greeting.
WHEREAS His present Majesty King George the Third, by His Letters
Patent under the Great Seal of Great Britain, bearing date at Westminster,
the Twentieth day of November now last past, did give and grant unto me,
the said William Pope, His special licence, full power, sole privilege and
authority, that I, the said William Pope, my executors, administrators, or
assigns, by myself or themselves, or by their or my deputies, servants or
agents, or such others as I, the said William Pope, my executors, adminis-
trators, or assigns, should at any time agree with, and no others, from time
to time and at all times thereafter during the term of years therein expressed,
should and lawfully might make, use, exercise, and vend, within England,
Wales, and the Town of Berwick-upon-Tweed, my Invention of "AN
INSTRUMENT OR INSTRUMENTS, TO BE USED JOINTLY OR SEPERATELY, FOR ASCER-
TAINING A SHIP'S WAY AT SEA, AND ASSISTING IN DETERMINING THE LONGITUDE;"
in which said Letters Patent there is contained a proviso, obliging me, the
said William Pope, by an instrument in writing under my hand and seal,
particularly to describe and ascertain the nature of my said Invention, and in
what manner the same is to be performed, and to cause the same to be inrolled
in His said Majesty's High Court of Chancery within six calendar months
next and immediately after the date of the said recited Letters Patent, as
in and by the said recited Letters Patent, reference being thereunto had,
will more fully appear.

page_text: NOW KNOW YE, that in compliance with the said proviso, I, the
said William Pope, do hereby describe and ascertain the nature of my said
Invention, and the manner in which the same is to be performed, by the
Drawings or diagrams hereunto annexed, and as follows, that is to say:-
The first part of the said instrument or instruments is shewn in Figure 1.
This part I have denominated the marine automaton. The following is a
N.B. The mercury falls
description thereof:-B, the harness of the magnet.
on the harness of the magnet into a groove, which conveys it to lower
grooves 34, which then conveys it into divisions answerable to the points of
the compass. D, the first reservoir; E, second reservoir; F, index to shew
the miles and tenths by the rise of the mercury in the small glass tube 29;
G, the floating valve, to keep the fluid to one height; H, the cock work;
I, i, i, i, i, glass or other tubes; K, the conducts to convey the fluid after it
has passed the harnessed magnet; 3, the plate glass, or metal, or other
substance to stop and open the glass tubes; 4, 4, the two pipes that convey the
fluid down to the harnessed magnet L; the magnet M, one of the receptacles
for retaining the fluid; N, the pump to force up the fluid (through the tube
No. 25) to the reservoir D; O, O, the pipes; or one of them, to convey a
portion of the fluid from one side to the other, and so to preserve an equili-
brium; T, the dial, to shew the rate at all times by inspection; A, the log;
B, B, the springs or weights, to counteract the log; C, C, the rack (connected
with the chain 12) moved forward or back by motion from the pinion W in
the centre of the wheel 18; W, the pinion into the wheel that works the
rack C, C, and draws the chain 12 that moves the plate 3, opening the orifices
of the tubes I, i, i, i, i, to let down a fit quantity of fluid; 13, 13, 13, 13, the
pulleys, that carry the chain 12; 14, 14, two poppets that support the work or
machine; 15, the gimble; 16, the rack connected with the chain 12, and
gives motion to the clockwork; 17, 17, the horns which the gimbles work
on; 18, the wheel that is drawn by the log; 19, the pulley which the log
rope passes over; 20, 20, the framework that keeps the wheel in its place;
21, the nuts that screw up the framework; 22, 22, stops that prevent the
rack going beyond its place; 23, the line that moves to shew when it's time to
wind the fluid up; 24, a covering to protect the reservoir; 25, the tube that
brings up the fluid; 26, the ears which hang up the machine to the gimbles;
27, the cylinder to measure the fluid; 28, a cock to let out the fluid from the
cylinder; 29, the glass tubes to shew the height of the fluid; 30, the pipe for
the pump; 31, the handle of the pump; 32, the line, with its nobs, to shew
when to take off the account; 33, the cocks to let out the fluid; 34, the lower
divisions which receive the fluid from the harness of the magnet; 35, the

page_text: notched wheel that regulates the quarters; 36, a spring to keep the rack into
the teeth of the pinion; 37, marked in dots, is a pan to guide the fluid into
the cylinder; 38, a barometer. N.B.-The outside of the body is represented
as transparent, merely for the purpose of shewing the divisions which receive
the fluid, and on the top of this, under the magnet, are marked the common
points of the compass, but reversed in their order.
The
The second part is called the current log, and is shewn in Figure 2:
following is a description thereof, viz:-Let the navigator be furnished with a
small compass card and the instrument; first put the current log into the
water, veer out the line, and be careful not to give it the least impediment, and
hold the end of the line in his hand until he feels a check of the current log;
then apply a compass card under the line to know the course; then draw up
the log, and look what is brought round on the index, and you have the course
and rate per hour.
.
.
The instrument on a three-inch scale: No. 1, the part a, a, is to be set to
a right angle, as shewn in dotted outline, when the log is let into the water.
in order that the line shall cant the instrument round to the side that the
index comes out at; No. 2, a lower part which draws out in the direction of
the line, and brings the wheels b with it, to vary the angle of the index;
No. 3, the spring that stops the wheel or index to its place until it is read off;."
No. 4, the frame of the wheel or index; No. 5, the button that raises the
spring to keep it from grating against the notches when preparing for opera-
tion; No. 6, the wheel or index made fast to the arm or piece 1, 2; No. 7;
the brass screw to receive the weights; No. 8, the temporary weights; No. 9,
the weight; No. 10, the nutt to keep on the weight; No. 11, the line;
No. 12, the compass box; No. 13, the engraving for the index is on the
wheel on the opposite side directly under 13; No. 14, the beveled notches that
the tongue of the spring falls into.
Figure 3 éxhibits the method by which the index of the current log is
graduated, and also the mode of using the same. Let the line or cord suffer
the log to be 30 seconds falling to the end (which period of falling is regulated
by occasional weights on the instrument), which is the same part of an hour
as 51 feet is of a nautical mile, and it is to take 60 fathom of line precisely
from the surface of the water, which shall be the first point or line given.
Then let 51 feet be the horizontal line whereon the boat is supposed to be
carried by the current. This shall be the second, and find a third on the wheel
or index of the instrument, which third shall point out the rate of the current.
The diagram above, wherein is explained the manner how to graduate the
instrument, drawn on the Sth of an inch scale as regards the line or cord of

page_text: the instrument, but not the index wheel, for this may be of any size. Let B
be the first line of the instrument, 120 eighths of an inch for 60 fathom.
Let D be the second, as above, on the surface of the water where the boat is
drifting. Let E be a third line, drawn from the lower point of B to the first
distance on D at F, which first distance from D to F is 51 feet, upon a scale
of 1/8th of an inch, as above, for the drift of the log, or, what is the same thing
in this case, the boat which drifts as the log would in 30 seconds at one mile
an hour 51 feet. Let a piece of circular paper represent the wheel be of
the same size, and be placed by a pin through its center into the point of the
bottom end of the line B, having à line across its center parallel with B.
Then from that point draw a line to the first division on D across the circular
paper, and you have the proportion on the circle to one mile per hour of the
current. Then to find the remainder, take the first distance on the line B,
viz, 120 eighths of an inch (which would be 60 fathoms if the scale was a
foot). Then place the one point of the dividers in the second division or
second 51 miles on the line D, and the other in the line B; let it fall where
it may, and draw a line from these 2 points, placing the card as before, and
where the line cuts on the circular paper is the proportion of the second line
on the wheel or index P, and points out two miles an hour. Pursue the
same rule for the remainder of the graduations, and you have the deviations
on the wheel of your instrument up to 12 miles an hour. The steering card
which I prefer for the said instrument or instruments is exhibited in Figure 4.
The following is a description thereof, viz:The card is perforated and the
needle is both horizontal and dipping. The advantages over the common one
consists in its being stronger and steady to its point. The cause of the first
that it is a dipping needle, and receives the influence or effluvia of magnetic
attraction at the end, for a magnet will draw more at the end than at the side:
The second because the horizontal is counteracted by the perpendicular motion
of the dip of the needle, and the perforation of the card suffering the air to
have a free course, by which means the card is not thrown aside by the
motion of the air in passing from below to above, and from above to below.
When the card is to be made use of for the purpose of allowing the variation,
the point is not to be cut out, because the divisions thereon will be necessary
to know how far to slide the magnet to the variation. No. 1, the dipping
needles; No. 2, the bass or plate to hold the axis and to receive the agate;
Nos. 3, 3, the screws that tighten the axis, and remark that instead of holes
being bored to let in the axis, there is a a small groove cut across
the plate, both for truth and convenience of taking to pieces; No. 4, the
screws with perforated heads to take the axis; No. 5, the plates to steady or

page_text: keep the axis in its place; No. 6, the nuts to keep on the steadying plates;
No. 7, the agate; No. 8, the form of the perforated card; No. 9, the point
that is cut out, to be riveted on the south end of the needle. N.B.-The
composition with which the needle or magnet is to be fed is pulverized load-
stone, fastened on by gum shelac dissolved in spirits of wine, or fixed or
fastened on by any other matter, it desired or thought requisite.
T