INSTRUMENT FOR NAVIGATIONAL PURPOSES
Year: 1884

page_text: PROVISIONAL SPECIFICATION..
I, WILLIAM CLARKE KEITH, of 5 Baffin Street, Salisbury Place, Dundee in the
County of Forfar, Scotland Gentleman (Invalide) do hereby declare the nature of
my invention for A NEW INSTRUMENT FOR NAVIGATIONAL PURPOSES to be as
follows:-
"1
and
ог
and
"
for its
ог
A Mechanical Compass or Instrument, which in its "construction
movement is entirely independant of all magnets" all polar or other
attraction called "needles."-A self-acting compass which shews Greenwich-time
whether the vessel be at the Equator, or at the North or at the South-Pole or in
any other position whatever in any waters no matter where during her voyage→
An automatic compass entirely unaffected by any atmospheric or any other electric
or magnetic influence or attractions, a purely mechanical contrivance or Instrument
which instantly shews and determines the "true"-course the vessel is "heading "-
determines also, at the same instant whether any "deviation" has arisen in the
vessels-" pole "-compasses-shews and determines at same instant whether such
"deviation" (if any) be " easterly" or be "westerly"-deviation," shews and
measures the "amount" of any such "westerly" or "easterly' " deviation
respectively, and in each and either case (of ships-compass-deviation) shews and
determines the " course being steered as being the "apparent" but not the
"true"-course-and determines the "amount of " error "of the course steered
when such "error" arises from any compass-deviation aforesaid.
"
"
This Instrument equally instantly shews and determines where there is no
'compass-deviation" of either "easterly or westerly" and in such cases shews
and determines the "apparent " to be the true "-course.
and
or
"
Being absolutely free from the defects of "variation "-" deflection "-" aberration"
local-attraction either "in-bord" or from any "iron-bound-coast," the vast
importance of such an Instrument in determining longitudes and with every thing
relating to Marine-Navigation are items so apparent as not to call here for any
details in respect thereof, while I try to describe the Instrument itself.
The details of the various phases of the Instrument, one hundred and twenty-
eight (128), being sixteenths of a "point" of the compass, could be clearly
By Greenwich-time, I mean Greenwich-Meridian for Longitude.-W. C. K.

page_text: explained only by the aid of elaborate-diagrams, but its operation is very simple,
and each position is very decidedly marked.
" and
As distinguished from the Active" Instrument, the one, now under con-
sideration, and of which the photos sent will aid you clearly to its "form
"construction," is an Instrument that can be placed on a table in the cabin, or in
the Captains-state-room or elsewhere on board, in which position (so as to distinguish
it from the other) it inay be called "Passive" that is, the latter requires to be set
or adjusted to certain lines in the manner hereafter described.
The table on which to place this "Passive "-Instrument is any suitable table or
stand that is a fixture in the vessel; the Instrument shall be firmly bolted to any
such table, and be made "fast" in such position that it (the Instrument) shall be
either exactly in line with, or be exactly on any line parallel to, the line of the
keel, and with the bead of the Instrument towards the bows of the vessel.
Or, in other words, the line running from stem to stern of the ship, and
correctly represented by the "pole "-compass when the vessel is swung for its
adjustment, or any line correctly parallel thereto, on which the Instrument may be
set shall exactly bisect my Instrument in, any whatever place in the vessel where
it (the Instrument) shall be "located."
Whenever it may be desired to test the "course -an arm-piece or index-
point (of the Instrument) is then set or moved by hand until it (the course) shall
be in line with the exact number of "points" or sections of points of the "pole "-
compass, or other compass by which the vessel is "stecred "-or, in other words, the
"
course being steered is." laid-off" on the Instrument, an index of the Instru-
-ment-is-then-also-set-in-position-The-Instrument..would.then stand.at.North.in.so
far as North is correctly shewn by the "pole "-compass.
"
These "arm-pieces" or indexes are then made fast at the points indicated, so as
to prevent them slipping, and the piece or index that represents the vessel is then
swung round until its end or point bears exactly in line with the line which bisects
the Instrument on the table or cabin-table where the Instrument is placed.
26
"
The moment these 2 (first named) points or indexes correspond by the one being
exactly above the other, my Instrument shews the " course by Greenwich-
Meridian, that is being steered, but any the slightest say or eventh of a
point" of difference (if any) between the "course" shewn by the Instrument and
the "
course" shewn by the "pole "-compass (index),-will represent the "variation,"
error or "deviation" from the "true"-course-and enable the Captain instantly
to see that the " course "he is steering is or is not the "true course.
"
"
My Instrument will also shew him what the "true"-course he is steering really
and exactly is, and the difference between the course he is steering as indicated
by his "pole-compass" and the "true"-course shewn by my Instrument will also
shew him that the "amount" of such "error" in his course, if any, is exactly the
"amount" "extent of the "deviation" or "aberration" from true North by
Greenwich-Meridian that has arisen in his "pole "-compass, my Instrument has
no "needles," nor " magnets," nor "springs" whatsoever.
or
This "Passive "-Instrument could not correctly in the strict sense of the term be
said "to serve as a Mariners-compass,"-if the use of such a term or definition is
capable of being limited to mean a compass used as a "pole "-compass, or a steering-
compass, or what may be called a "sailing-compass "-and the distinction is far
more real than it appears at first sight-The other application of my Instrument
(Active), (not at present under consideration) would enable him to steer and to
steer correctly-but this application of my Instrument, "Passive" enables the
Captain to see any "error" that has already arisen in the course he is steering
where such "error" originates by reason of the "deviation" or other defect in his
ordinary-compasses,--shews him what that "error" really is, and puts him on his
guard to get his course rectified.
This important part of my Invention places it within the power of the Captain
or his officers, while sitting in their own cabins to ascertain by night or day, or in
fog, or in storm what "amount" of "error" is being caused in the course steered,

page_text: " or or
through the defects of their "needle "-compasses " arising from "deviation
attraction" or any other influence whatever, and it is to avoid the possibility
or risk of this essential-element of this my new Instrument being left unprotected
by my Patent, that I have tried to point out wherein such essential-clement
exists.
Seeing that it follows as a natural sequence or result, it is scarcely necessary
here to remark that this my new Instrument overcomes another great difficulty
(in navigation)-i e-that in fog, or in storm, or at any, and at all times during
which no "celestial-observations" can be obtained to find the "true"-course,―
my Instrument,, at all times, entirely dispenses with the otherwise requisite
assistance of an "Azimuth-compass," and also with all the complex-calculations
necessary to determine the "variation" of his ships-compasses,-simply because
it (the Instrument) at once gives the correct result, without any either solar,
or lunar, or stellar-observations" whatsoever, and it (the Instrument) instantly
furnishes the Captain with the requisite information without his being obliged
to wait for many hours, perhaps for days, in uncertainty as to his "true"-
course until such aforesaid observations" could be taken, till such complex-
calculations could be made-or what is called "worked-out."
"
and
ог
This new Instrument can also as readily, be used in what may be called a
"reversed"-action,"-in which (case) it can be set or placed in any position or place,-
and the "indexes" being set, so to say, in an "inverted "-manner
will give
equally instant, and equally definite results.
"3
In itself (the Instrument) contains check-counter-check, an cross-counter-
check, (very visible) in every instance, and in this reversed" or "inverted "
form (or mode of using it,) is a fourth-proof of its absolute-mathematical-
correctness.
In all its positions (or phases) when "reading-off" the "true"-course or whatever
"deviations" (if any) it, (the Instrument) presents to the eye such clearly well
defined & distinctive signs, as, at a glance to enable one to see, as rapidly, as to
read it.
The constant facility given by the Instrument, for immediate reference, and the
information it so instantly and correctly gives, will, it is said, warn many a Captain
to give a "wider-berth" to the land or coast in his "course," and instead of, as
now, the first intimation of "error" being his finding his vessel "stranded,"
"aground," or on the rocks, my Instrument will in good-time, if consulted,-—thus
warn him of his danger, and will thus aid to save his vessel and cargo from wreck,
and by consequence also to save the lives of his crew.
By request. The above shews the amended title, and gives fuller details.
Titel Dundon this f
100-

page_text: I, WILLIAM CLARKE KEITII, of 5 Baffin Street, Salisbury Place Dundee, in the
County of Forfar Scotland, Gentleman (Invalide) do hereby declare the nature of
my invention for NAVIGATIONAL PURPOSES by the above named Instrument, style
called "Passive" and in what manner the same is to be performed, to be par-
ticularly described and ascertained in and by the following statement:-
The
Construction, discarding for the moment the six (6) appliances or accessories
which are shewn round the Instrument, and to be described further on,
largest disc (brass) is, in its outer edge engraved as a compass-dial and is divided
into 128 parts each equal to one quarter of "a point of the compass"
-or 32
"quarter-points" each again subdivided in quarters, and each of these sixteenths
are numbered both to the right and left 01 to 64,-the latter number thus
terminating at the other circumference of this plate.
This plate is carefully adjusted on the sole-plate, and is firmly aflixed thereto by
screws in its inner or covered face.
The sole-plate is of plain walnut-wood, any other wood can be used, and the
bright-bands are to prevent it "warping” And instead of whatever metal, or
wood, or material herein named,-any other metal, or material whatsoever, may,
and will be used, in place thereof.
Section 1, For more easy explanation the Instrument if dismounted may be
said to consist of 4 main sections, or parts,-the first section being the largest
(brass) disc, and the sole-plate.
"
Section 2, Consists of a smaller steel-disc also engraved as a compass-dial divided
into sixteenths of a point" or being quarter-points" subdivided each into
fourths, on this plate are also engraved the "degrees " 0 to 90,-90 to 0 &c round
its inner visible circumference.
The smaller upright brass-band is divided into 32 "quarter-points" each thus
engraved respectively North, North by East, Nor-Nor-East Nor-East by North &c,
from left to right all round this band.
This upright-band is mounted on an inner walnut-plate and is securely fixed
thereto, It has a projecting point or "indicator" extending over its own steel-
plate on to the brass-one,-this band and its inner wooden-frame are covered by a
brass-plate on whose outer-edge can be engraved the "hours, minutes & seconds,"
and on its projecting covering-point is engraved a large fleur de lys.
'
This steel-plate, together with this brass-band, and its upper-plate form what
may be called Section 2.
**
Section 3, Consists of a walnut-dise having on each of its upper and lower faces
a thin steel-plate,-each of these three (3) pieces having a point or indicator," the
point of the upper-plate being engraved an "arrow "_ This Section 3 carries a
key-slit" carefully cut in such position that the flat steel-key of the central-piece
of Section 4 shall exactly fit thereinto, when the points or "indicators" of these
2 sections exactly overlap each other.
"
The lower steel-plate of Section 3, rests on the upper-plate of Section 2, and on
the face of the upper-plate of this same Section 3 there rests the face of the lower-
plate of the next Section 4.

page_text: The Sections 2 and 3 as also the brass-plate of Section 4-are made lighter by
being "cut-out" in something like a "Maltese-cross" leaving a central ring, four
(4) arms, and an outer-edge, so as to prevent friction and to provide that all work
smoothly.
Section 4. Contains the gearing, which is enclosed between the two (2) brass-
plates which form the upper-part of the Instrument, the dark band of walnut
serves to keep out the dust, these 2 plates are firmly held together by the five (5)
brass-bolts, whose "washers" and "nutts" shew on the upper-plate or "face-
plate," the lower plate rests flush on the upper-thin-steel-plate of Section 3,-the
upper one or face-plate" carries three (3) fixed pointers or "arrows,"-through
this face-plate" project the six (6) square ends of the spindles, three of which
(spindles) carry the three other arrows or pointers which revolve but whose
compass-dials are fixed, the other three spindles carrying the three (3) compass-
dials which revolve but whose "arrows or pointers are fixed to the "face-plate
(as already noted).
<r
"
"
Thus there are three (3) fixed arrows with revolving dials, and three (3)
revolving arrows or pointers with fixed dials, the three arrows which are fixed
are the two (2) in rear of the central-piece and immediately in front of it, and
the dials of these revolve, the three arrows or pointers which revolve are the
smaller 2, one of which is on each side of the central-piece and are in front or
forward of the larger ones, the third arrow or pointer which revolves is the small
one over the very small dial immediately to the front forward, and it is the dials
of these three (3) that are fixed on the "face-plate."
By displacing the three (3) revolving arrows and unscrewing the five (5) "nutts
& washers," and removing the bright steel circular band or "collar" which is round
the projecting upper-part of the central-piece,--the "face-plate comes clear off, and
gives access to the gearing.
The "central-piece" passes down through the Instrument, and is received into a
brass-socket which is fitted into the walnut-sole-plate,--and preserves this central-
piece always in a perfectly upright position.
At a point on a level with the other gearing, this central-piece carries a geared-
disc or wheel, firmly secured thereto,-and into this central-disc are geared the disc
immediately in front and in rear of it, these in turn are geared into the other
discs or wheels,-the whole thus deriving indirectly their movement from the
central-piece as "motive-driver."
This central-piece thus forms the pivot or axis round which the Sections 2, 3,
and 4 are very carefully fitted and have their movement.
At a point or place where this central-piece passes through the Section 3, the
2 ends of a flat-steel-key project from the tube of the central-piece so as to fit and
rest in the "slit" cut in the section 3 (already noted)-This key consists of 2 steel
or iron pieces the inner ends of which are securely fixed into a brass-collar, through
which (collar) passes the screwed part of the steel-pin which goes down the centre
of the tube of the "central-piece."
A slide or "slit" is cut through the sides of the tube of this central-piece,-It is
through this "slide" in its tube that project the ends forming the key,―This key
can be lowered (at pleasure) from Section 3, into a similar "slit" (as in Section 3)—
which exists in Section 4,-
-or vice versa, can be raised.
To lower or raise this steel-key without disturbing the Instrument, after it is
"Bet-up," '-access to the head of the steel-pin in the tube is obtained by unscrewing
the brass-cap which covers the head of the central-piece, the steel-pin retains its
Dormal place, but with the aid of a turnscrew it raises or depresses the brass-collar
of the key-piece, the ends of which by passing through the slide or "slit" in the
tube are held in position.
"
Further to protect the internal-gearing, and to keep the upper and the lower
plates equi-distant from cach other, and incapable of being forced inwards at the
centre, there is placed both above and below the geared-disc (aforesaid) a fixed
flange or rim securely made fast to the tube of this central-piece, the centre of the

page_text: inner face of the upper-plate rests on the one flange or rim,-and the lower flange
rests on the inner face of the lower-plate,-This arrangement, together with the
outer bolts & "nutts" and the walnut-rim or disc, keep these 2 plates always
parallel, & secure the smooth working of the gearing, & free from damage.
In "setting-up" the internal-gearing, previous to screwing on the "face-plate,"
great care is taken so that the 6 spindles whose square ends project through the
face-plate, shall be so "set" and "driven-home" into their respective wheels, as to
secure that the revolving compass-dials and arrows carried on these spindles or
"pinions," shall, when at rest on the face-plate, present (the compass-dials) their
North and South exactly in line (or if so desired then at right-angles) with the
fixed "arrows,"-and that the smaller revolving arrows, in same manner shall
present their " Bèches" or heads in line with the fleur de lys of the smaller
compass-dials which are fixed to the "face-plate."
The wheels of all the internal-gearing are so distinctly marked as to permit this
being easily done, and once they be so "set" and the "face-plate" screwed down,-
the larger (fixed), and the smaller (revolving) arrow on each and either side of the
central-piece, shall be in line respectively with each other, and the 2 lines formed
by these 4 arrows shall be exactly parallel,-The smaller (fixed) arrow will present
itself forward, intermediate, but also parallel with the former, and the smallest
(revolving) arrow right forward at the "point" of the face-plate, shall be in line
with the other.
and
ог
For all further details of the internal other gearing of the Instrument, and
so as to avoid useless repitition thereof, reference is here made to the various
drawings of tbis Complete-Specification_where these_(gearing).are_so_clearly_shown
as not here to call for a verbal description.
But it may be as well to again record that this new Instrument has no "needles,"
magnets," nor "springs" whatsoever.
nor
"
As to the 2 main-dials on the face-plate these are specially made in duplicate so
that the "movement" of the one shall exactly tally and correspond with, and so
counter-check the movement of the other.
These 2 dials are also each divided into sixteenths of a point, and in-as-much,
(and no more, and no less) as the fleurs de lys of these revolving-dials (in testing a
course) move away from under the fixed arrows respectively shewn over them,--any
the amount of such revolving movement correctly coincides with and exactly
represents the amount in sixteenths of a point by which the vessel has moved away
from "North"-and thus the line of the "head" of each of these fixed arrows over
their dials is, (after testing a course) the indicator of the course steered-and the
course thereon shewn shall "concord" with such course as is also shewn by the
larger-dials of the other Section 1; and by the dial & by the letters on the brass-
band of Section 2,-and each and all of these shall thus counter-check cach other.
The next 2 smaller (similar) dials (fixtures) on the face plate are also made in
duplicate, so that, in same manner (as above)-their revolving-arrows ahall in
their relative movement each be check and counter-check the one to the other
respectively.
The revolving movement of these 2 arrows exactly coincides with that of the
2 main-dials (aforesaid),-The positions taken up by these arrows not only indicates
the course on each their own respective dials, so that the course indicated on the
one set of dials (fixed), shall tally with and counter-check the course shewn by the
other set which revolve, but also that the arrows themselves (even apart from their
dials), shall, (the revolving as towards the fixed ones) take up such relative positions
towards each other, and so prominent, as that, instantly the eye rests on the face-
plate of the Instrument, in themselves alone, these arrows distinctly and clearly
define the course the vessel is "heading."
So much for construction, and now as to its mode of action.
Any movement (by hand) which displaces the point or "indicator "of Section 4
(which carries the gearing) from exactly overlapping the point or Indicator of
Section 3, (into which Section 3 the key of Section 4, is set) will at the same

page_text: moment set in motion the 3 revolving-compass-dials and the three revolving-
arrows shewn on the face-plate.
The normal position of all the 3 points or "indicators" being one for each of the
respective Sections 2, 3, and 4,-is that they exactly overlap each other "heading-
forward," and are on a line which bisects the sole-plate in its length,-which line
thus also, so to say, bisects the Instrument and all its gearing, dials, and arrows
into 2 equal halves,-and also (bisects) 2 of the six accessories (aforenamed) to
which reference is here necessary,-viz, the one at the front, and the other at the
back-end of the sole-plate-the former consists of a plate or plates terminating
in a point forward, this plate carries a long-thin-upright-steel or other indicator "-
and is to serve as "indicator-of-direction,"-heading forward-the other piece or
accessory (at the back-end of the sole-plate) carries a small horizontal-plate with
a scale engraved thereon, and 2 arms or pointers there for, (the special use of which
is noted further on), and the line (aforenamed), in its length bisects the scale of
this piece, on the sole-plate.
The line so indicated as bisecting the Instrument, shall, in fixing the Instrument
exactly and correctly accord with the line of the keel,-(or in effect the line on
which the ships-pole-compasses are adjusted,) on which line, or on any line exactly.
parallel therewith, the sole-plate of the Instrument) shall be bolted down and
securely made fast to any suitable table or other furniture which shall be a fixture
in the Captains or other state-room, or in any of his or his officers-cabins, or other
place in the vessel, and shall remain so fixed in any such position.
-
When the Instrument (always ready for it) is carefully so set in position, which
is easily done by the exercise of some little care & attention, the front-indicator due
forward, the Instrument is then ready for use.
The sole-plate of the Instrument, being thus made a fixture in the vessel, the
front-indicator clearly shews and always determines the exaot direction in which
the vessel is "heading" & during her voyage.
MODE OF MANIPULATION OF THE INSTRUMENT.
As already said in my provisional-Specification, its mode of "operation" is very
simple, and each position is very decidedly marked, but that, "the details of the
various phazes of the Instrument, one hundred and twenty-eight, being sixteenths
of a point of the compass, could be clearly explained only by the aid of elaborate
diagrams for the reason that only one position could clearly be shewn on each
drawing."
"
"
East-by-South,-being only the "apparent" but not the "true "-course steered,
instantly places the whole Instrument at " discord," the fleur-de-lys or indicator
of Section 2 stands to the left of the arrow or indicator of Section 3; the
indicator of Section 4 stands to the left of the "indicator-of-direction "-Each of
the larger-dials on the face-plate shew (not East-by-South, the course "laid-off")
but East-by North, and so also do each of the 2 revolving arrows respectively in
front thereof, the "compass-points" engraved on the steel-plate of Section 2
discord with the equivalent points on the large-brass-plate of Section 1,-the former
being also to the left of the last-named (Section 1); and a further "discord" will
also be found under the indicator of Section 4,-in that, on this brass band (of
Section 2) at that point it clearly shews due "East."
Such as above, is the "discord" instantly produced (on the Instrument) by the
mere act, however rapid, in laying-off" a course of the vessel, which though the
apparent," is, in fact, not the true-course steered, and the greater the "deviation,"
so the greater the amount of divergence or "discord."
"
"
"
As compared therewith, the result of an "apparent "-course, say East-by-North,
if laid-off" on the Instrument discords the relative positions of all the aforenamed
indicators" and (discords) also the larger-dials of the Sections 2 and 1;-as much
to the right, as East-by-South "discords" to the left of cach other respectively,-

page_text: and while each of the larger-dials on the face-plate, as also the revolving-arrows in
front of them will shew East-by-South (instead of East-by-North, the course
laid-off on the Instrument) still the letters on the brass-band of Section 2; imme-
diately under the indicator of Section 4,-will continue to shew due "East."
And in both these cases East" is the "true-course steered, as will instantly be
seen by the Instrument the moment it (the Instrument) is set in "accord,"-and
thus deviations" be thereby adjusted.
"
دو
First to "lay-off" a course, and to shew its "deviation,"-and then to "correct"
the "deviation' so as to shew the true-course; can each very easily be done (on
the Instrument) in about 10 seconds of time.
To correct the deviations (aforenamed) which are shewn on the Instrument,-
place the "indicator" of Section 4, in line with "direction-indicator" the result is
instantly seen on the "face-plate," by the 2 revolving-dials shewing due "East,"
and the 2 revolving-arrows also due "East," and therefore at right-angles with
the fixed-arrows respectively in rear of them, these also (now) shewing a duc
"East " course, and therefore by the one single move (as aforesaid); 3 points of
"discord" dissappear.
Next operation is to place the indicator of Section 2, so that it exactly underlap
the indicator of Section 3, the instant result is that, (this included), three (3) more
points of discord have ceased to exist, the other being that the compass-points of
the dial of Section 2, now accord with the equivalent-points on the dial of Section 1,
and the third is, that the letters due " East
on the brass-band (aforenamed) now
are in line with the front-indicator which is the indicator-of-direction."
"
The entire of the Instrument now stands at accord, and the measured-distance as
between the "direction-indicator, (first or original point of departure from North),
and the "arrow or indicator of Section 3, is 32 sixteenths, equal to one fourth of
the compass-dial, or in other words, the exact equivalent of the distance from
North to East, this being the amount "laid-off" on the Instrument to test the
course.
st
4ths of
there-
It is well here to remark that the amount which requires to be laid-off to test
a course, (i e to test any course already first previously laid-off on the Instrument)
is always correctly defined by the Instrument itself, for instance the absolute
result of laying-off East-by-South (aforesaid), is, that the indicator of Section 2
stands at (figure) 36 on the plate of Section 1, but it is equally evident (on the
Instrument) that the "full-point" on the plate of Section 2 stands at figure 4 on
the plate or dial of said Section, therefore the figure 04 represents the amount of
the discord,"-and as the Instrument itself also shews that these 16th
" discord " are in excess, and are to be deducted; therefore as 36 less 04 give 32,
so therefore 32 is the amount of the test and represents the figure at which to
lay-off the testing-indicator of Section 3 in its distance from the front or direction-
indicator, for the same reason, that in the case of East by South, the amount of
"discord" shewn by the Instrument to be in excess requires to be deducted;
fore in the case of East-by-North, where the "full-point" on the dial of Section 2
discords with the dial of Section 1, to the extent of the figure 04 beyond the
figure 00,- and as the Instrument thereby clearly shews that this amount (of
discord) must be added, in addition to the figure denoted by the indicator of
Section 2 on the dial of Section 1,-and as the unfailing result of laying-off such
course, is East by North (on the Instrument) causes the indicator (last-named) to
denote the figure 28 on the dial-plate of Section 1, therefore as 28, plus 04, gives 32,
so again in like manner is 32 the figure (determined by the Instrument) to be the
point at which the testing-indicator of Section 3, must be set on the dial of Section 1.
In the 2 instances named it is found by the Instrument that the number of
"points" or sections of points as between the "apparent" course laid-off; and the
position of the fleur-de lys (at the point taken up by it over the brass-plate or
dial of Section 1), are only 32 in each case and it positively results that such a
position cannot admit of an East by South course, nor of a course "East by North

page_text: either of which would if correct ie ("real) not discord the Instrument, but would
each mark 36 sixteenths without discord, instead of 36 sixteenths plus the discord
already described, and so clearly determined; by the Instrument.
If it be well borne in mind that
"
deviation" (in itself) of whatever nature), can
in no manner extend the respective distance between the North and any other
given point of a compass-dial,-and that, while however much it (deviation) may
alter the relative position of any one given point (of the compass) as towards any
other given-point (of something-elso), still East and West will and must be 32;
South will & must be 64; South-West and South-East will & must be 48
sixteenths by measure from any whatever position in which its fleur-de lys or
North may be found, and all the other intermediate-points & sections are equally
well. defined from this fact some insight will further be gained as to the manner
of the function (or modus-operandi, so very hard to describe in words) of this new
Instrument now under consideration.
"
"
To dismiss the subject of East by North, and of East by South it remains still to
shew the practical-result obtained, which is, that therefore the vessel was
heading" a true"-course 11th or one-quarter-point farther to South than its
apparent "-course East by North shewn by the ships-pole-compass, and that in
the case of East by South the vessel was heading a true-course 14th, or one
quarter-point farther North than was the "apparent "-course on which she was
being steered.
"
In the case of a true-course being steered, say South-East, such course when laid-
off results in the fleur de lys of Section 2 indicating exactly the figure 48,
(without "discord"), and the testing-indicator of Section 3 being laid-off from
the direction "-indicator in front, by exactly that figure (48) of points or
sections of points;-The Instrument in all its larger plates & indicators as also in
all the smaller-dials, & fixed, & revolving-arrows on the face-plate, will all
"concord" in shewing exactly that course (South East).
And such "concord" (of the Instrument) will as clearly & definitely show itself
in the case of South-West (also 48), or of South which will (on the Instrument)
shew 64, and so also with any other point (or Sections of points as towards their
exact figures respectively whatever these may be, which it may be desired, or be
requisite to lay-off and test.
And in actual-practise, it is said to be as needful to be assured (by proof) that
the course-steered is the "true "-course, as it is (needful) to know exactly what is
the "deviation," if any.
It has already been said in my Provisional-Specification that the Instrument can
be "operated" in various ways, as check & counter-check and even in what, may
be called, an inverted-form of action,-more forms than one are therefore (by the
Instrument) available in determining a "course," and while such various modes
(of operation) so as to get them into 2 classes, may, (in such a comprehensive
sense) be said to be the one, to lay-off his course steered; to find the "true "-course,
the other, to lay-off the true-course; to find bis "deviation" it is not possible to
enter here into these (very tedious) details beyond giving one example (to serve
for many others) of the manner by which the first operation (on the Instrument)
is to lay-off carefully the exact bearing of the ships-pole-compass, thus first to fix
(or arrive at) on the Instrument) his "apparent "-course, so as to determine what,
if any, is the amount of error, and this may be most briefly shewn, as follows.
By "bearing" the ships-compass-fleur de lys, indicates figure 40, & the vessel
is steering an apparent "-course due "East"; what is his error or "deviation " ?
test, from where is the figure 40; count-off 32/16ths; that shews 8 on the brass-
plate, at 8 set the " arrow of Section 3; "East his apparent course will be
under it exactly,-Next, from the "direction-indicator; (to the right) at figure 24
set the indicator of Section 4, the various dials &c on the face-plate will shew due
"East" & (and that is the course he thinks he is sailing),-Result is, that " East-
South-East' is in line with the "direction-indicator; thence to indicator of
Section 3 to 8 quarter-points; and that is his " deviation."
"
"
"

page_text: Should it be desired to test the result (as thereon shewn) it can as rapidly be
done by one or more of the other modes of operation, (already spoken of).
And as due "East and West, (in navigation) are the points and sections of
points the most affected by any whatever course of "deviation" it is much to be
desired that the Instrument be capable of the various "forms" of "operation"
(aforesaid) instead of only of one form.
As to taking the bearing of the ships-pole-compass,-it must here be clearly
understood that this is a matter which may best be left to the Captain or other
officers of the particular vessel using the Instrument, which must not be
'tampered" with, and shall not be set,"- -nor even moved, nor interfered
with in any manner whatsoever while such "bearing" is being taken.
"
The sole object of the " bearing " is to find the exact figure on the dial of
Section 1; and should any "compass" be used, it inust of necessity be a compass
of that particular vessel; aud any such compass shall and must be equally
defective, and to the same extent be as "vitiated” as is his pole-compass, for the
Instrument itself does not require any such extraneous-aid in working-out its own
(the Instruments) calculations or results, and therefore no other than a defective-
compass of that particular vessel is any use whatever; and would only cause harm,
instead of doing good.
While it is not possible to impress the above remark too closely on their
attention the projecting-head of the "central-piece is free to receive, and to act as
a pivot for, and to support, any, some very simple style of "platform,"-say,
consisting of a small piece of brass tube, 2 arms; and a small central-horizontal-
-covering-plate, or any other suitable-but-light form of thing (on which to stand such
a compass during the momentary operation of taking a "bearing," and which
"platform and compass can thus as readily, and instantly be at once thereafter
removed from the instrument.
Should this mode of taking a "bearing" of his pole-compass be found objection-
able as in the slightest degree affecting the steady (non-rotary) position of the head
of this "central-piece, and with the view & object of preventing any tampering
with it (the Instrument), and of keeping always clear the face-plate,-clear from
any obstruction in observing the ever changing positions of its dials & arrows;—it
may be preferable to obtain this "bearing" rather by affixing a small "vitiated "-
compass (or capable of being made vitiated, defective, or "deviated" to tally with
his pole-compass,)-on either side of the walnut-sole-plate.
Thus removing any such compass away from any contact with the Instrument,
(placed thereon), and this may be all the more preferable as it would at once
obviate alike any intervening interruption, and consequent loss of time, while it
would present, instead thereof, an ever-present means of obtaining any such
"bearing," available when required, under circumstances which might be most
unfavorable for doing so, either instantly or with the requisite exactitude,-and
thus not retard even for a moment, any instant reference to the Instrument in
instantly testing a course, whether by night, or day,-or in fog, or in storm, when
his pole-compass itself might be only imperfectly seen, or might be less steady
than is always desirable.
"
The point "North" determined by the Instrument is infalliby the exact same
"North" without any "deviation" whatsoever, as is the identic line (or its exact
equivalent) on which the ships-compasses were adjusted previous to her voyage,
and thus any
"deviation which has since arisen in her pole-compass, or others, can,
by the Instrument, which is absolutely free from all the defects of "variation,"
deflection," aberration " local-attraction" either "in-bord" or from any iron-
bound-coast, can, as aforesaid, (on the Instrument, as also ber course") be, at
once, measured, seen, and determined.
and
or
&
"
In my Provisional-Specification it has already been said, this Instrument can
also be used, not "bolted-down" but free, in any other place In being used in
this "form" free, the sole-plate then revolves on its own centre, and the supporting
or

page_text: table, any table, on which it would rest, would shew some line or lines simply as
guide and memo in this free, or revolving form, and as therein various other
details are given as to the Instrument and its purposes therefor to prevent repitition
it is as well, and is intended that, such Provisional-Specification (or its contents)
form part of, and be as if incorporated into this present, or final-one, (ie
Complete.").
Among the 128 positions (or sixteenths) "taken up" by the Instrument, each
ono in particular, being denoted by so many various phazes especial to cach
particular-position,-in check, counter-check, and cross-counter-check ;-each again
doubled when any special one is being cross-tested;-the few (positions) that have
been (attempted) to be described can give but a very faint idea of the distinct,
clear, definitely-" determined "-appearance (by the Instrument) presented in each
particular-case, and as among those (details) here referring to due East and West
(in navigation, especial points, as aforesaid); while space forbids other minor
details, it should here be recorded, that any, whatever "deviation" from due East
or West, discords the (other) relative positions of even the dials (on the face-plate)
as towards each other, On East and West their fleur de lys are in line,-and any
the slightest-deviation" in either direction causes them to lose, and to change
that marked-position,-one more instance or guide (very visible) when either the
one or the other
"
course is being tested, and further, the moment that, due "East
or West, be depassed, even the fixed "arrows, in their relative-positions towards
each other (by the movement of the face-plate) cease to be in line, & form still one
more point of "discord."
"
"Discord" and " concord," and how they arise, and how they shew, (on the
Instrument) have already, been, by these details, fully explained,-It remains how-
ever to mention the simple "operation" of laying-off any given-course, ie of
laying-off the course-steered," an expression herein so frequently used and more
especially, mentioned, in pages 12 and 9; It is the act of a moment and is done by
moving (by band) the Section 2, until the required letter on the brass-band of that
Section (2), shall be exactly in line with the line of the "direction "-indicator,―
and this operation" has nothing to do with the fleur-de lys of that Section,
which is left of itself to find its own, consequent, position.
s
The "dimensions" given, are those of the first (model) Instrument made,-
distinctness (of dials) and general strength & solidity are more than secured and
Instruments lighter and smaller,-probably 3 quarter-size, which would give the
drawings to be the " full-size of the Instrument; or even smaller Instruments
may be desired, and so will be made; but in any case this, any, whatever reduction
in size, in no manner. alters the relative-proportions, nor of its construction.
"
23
As to the scale, and 2 index-pointers (aforesaid) on the accessory at the back-end
of the sole-plate; such scale may best be a single, line along the line of the small-
plate; and the 2 index-pointers are, merely & simply, to give a facility of
shewing in what direction was last the "deviation," if any,-shewn on the Instru-
ment, instead of trusting it to memory-When no "deviation," the 2 index-pointers
are in line with the line on the plate; where "deviation has changed the one
lower-index goes (ie, is placed) one way-and the upper-index shews the direction
which the change has taken.
Сс
"
"3
"
compass"
Of the 4 remaining accessories or appliances, the 2 circular ones, in front, one is
engraved a clock-face, and has 2 pointers by which any intended change of
course at any given-hour can be set; the other one is engraved a
dial, on which such intended-course can be marked-off-say, by the one index-
pointer; while the other (index-pointer) simply points to the " course then being
run; these 2 accessories in no manner affect, nor are affected by, nor in any manner
connected with the Instrument itself, beyond being placed on the sole-plate,-and are
simply & solely a "facility" (in itself very desirable) by which a reference to the
Instrument, & to the latter (2 accessories) will shew to the Captain (or others) at
any hour (then past-due) whether the "course" was altered, or not; without his
going on deck.

page_text: The remaining 2, pointed-accessories or appliances, one at each corner at the
back-end of the Instrument, are each, simply the means by which the steel-plate
and the rest of Section 2; and the Section 3; can be firmly hell in any position
determination
to which they respectively may require to be set; finding the
"the vessel may
(by the Instrument,) of any other question, or, of what "course
then be
heading."
"
"
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim is
The mechanical-compass substantially as described in the foregoing Specification
and illustrated by the accompanying drawings.