CERTAIN IMPROVEMENTS IN SHIP'S PROPELLERS
Year: 1853

page_text: LETTERS PATENT 'to John George Truscott Campbell, Grocer,
No. 13, Lambeth Hill, Upper Thames Street, City of London,
Middlesex, for the Invention of "CERTAIN IMPROVEMENTS IN SHIP'S
PROPELLERS."
Scaled the 15th July 1853, and dated the 28th March 1853.
PROVISIONAL SPECIFICATION left by the said John George Trus-
cott Campbell at the Office of the Commissioners of Patents, with
his Petition, on the 28th March 1858.
I, JOHN GEORGE TRUSCOTT CAMPBELL, Grocer, 13, Lambeth Hill,
Upper Thames St., City of London, Middlesex, do hereby declare
the nature of the said Invention for "CERTAIN IMPROVEMENTS IN SHIP'S
PROPELLERS" to be as follows:-
My Invention I name the "Curvilinear" and "Curvilinear Pro-
peller."
The "Curvilinear" is of the following description, namely, a shaft,
a straight line, a leaf, and a worm.
The straight line runs longitudinally upon the upper part of the
shaft.

page_text: The inner edge of the leaf is placed upon the straight line of the
shaft; the outer edge of the leaf winds around the shaft, and is the
worm; the leaf is formed of curves placed reversely to each other on
each side of a perpendicular line, at the centre of the shaft.
At whatever angle the worm may be at the centre, it is continually
decreasing as it recedes towards the ends, when it lays around and
upon the shaft.
The Curvilinear Propeller" is one section, each of two "Curvi-
linears; the sections are taken from the centre of the "Curvilinears,"
and placed opposite to each other upon a shaft, thereby forming a
powerful instrument of propulsion.
The action of the propeller is rotary, and is to be worked in a hole
made in the deadwood of a ship, just before the sternpost.
The proportions, with detailed particulars, will be given in the general
specification, attached to which are drawings shewing the method of
forming the "Curvilinear" and the "Curvilinear Propellers."
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said John George Truscott Campbell, in the Great
Seal Patent Office, on the 26th September 1853.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I,
JOHN GEORGE TRUSCOTT CAMPBELL, Grocer, No. 13, Lambeth Hill,
Upper Thames Street, City of London, Middlesex, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Twenty-eighth day of March, in the
year of our Lord One thousand eight hundred and fifty-three, in the
sixteenth year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said John George Truscott Campbell,
Her special licence that I, the said John George Truscott Campbell,
my executors, administrators, and assigns, or such others as J, the said
John George Truscott Campbell, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thereafter during the term therein expressed,

page_text: should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for "CERTAIN IMPROVEMENTS IN SHIP'S
PROPELLERS," upon the condition (amongst others) that I, the said John
George Truscott Campbell, by an instrument in writing under my
hand and seal, should particularly describe and ascertain the nature
of the said Invention, and in what manner the same was to be per-
formed, and cause the same to be filed in the Great Seal Patent Office
within six calendar months next and immediately after the date of the
said Letters Patent.
NOW KNOW YE, that I, the said John George Truscott Campbell,
do hereby declare the nature of my said Invention, and in what manner
the same is to be performed, to be particularly described and ascertained
in and by the following statement, with the aid of the drawings therein
referred to, that is to say:
My Invention I name the "Curvilinear," and the "Curvilinear
Propeller." The "Curvilinear" is obtained from a line traced upon
the surface of two cones, fixed base to base, the said line to commence
at the base of the cones, and reversely make one revolution around
each cone, towards their apex; and if the adjacent parts be carved out
so as to allow the inner part of the leaf to form a straight line, and to
rest longitudinally upon the upper part of the axis or shaft, it will
form a leaf totally distinct from the worm of a "screw," as will be
perceived by referring to the drawings, Figs. 12, 13, and 14; for as
the screw is generated from a spiral line placed around a shaft, so
is the "Curvilinear" generated from a straight line placed longi-
tudinally upon the upper part of a shaft. The "Curvilinear" may also
be obtained from any other solid bodies, as a sphere, a cylinder, a
circular spindle, &c., &c., &c., due regard being taken to trace the line
upon the surface similar to that of the two cones before mentioned.
Therefore the "Curvilinear" consists of the following seperate and.
distinct parts; namely, an axle or shaft, a straight line, a leaf, and a
worm. The shaft or axis of the cones to be of any required diameter.
The straight line is placed longitudinally upon the upper part of the
shaft, Figs. 12, 18, and 14. The leaf is produced from various curved

page_text: lines placed in opposite directions to each other, on either side of
the centre line A, B, Figs. 12, 13, 14; the curved lines to be of
equal lengths, and placed at equal distances upon the straight line of
the shaft; the inner ends of the curved lines are to commence from
the centre of the shaft, Figs. 12, 13, and 14. The worm is the line
traced upon the surface of the two cones, or is produced from the outer
ends of the curved lines, and winds around the shaft, so that the
"Curvilinear" has no plane surface, but curved surfaces, and cannot
be made from or represented by any plano whatever; therefore the
"Curvilinear" is a perfectly moulded instrument. There are three
kinds of the Curvilinear; " first, the inner curved line "Curvilinear;"
second, the outer curved line Curvilinear;" and, third, the mixed
line Curvilinear."
The
Curvilinear Propeller," Fig. 4, (which I consider the best,)
is obtained from one section, each of two "Curvilinears," the reasons
for which are obvious; by referring to Figs. 12, 13, and 14, it will
be seen that the leaf proceeds from, and is attached to, a straight line
running along the upper part of the shaft, which leaves the under
part of the shaft free; and as only the middle section of the "Curvi-
linear" is best adapted for propelling, it is evident there must be two
"Curvilinears" to produce one Curvilinear Propeller;" or, in other
words, it requires the middle sections of two "Curvilinears" placed
opposite to each other upon a shaft to form a "Curvilinear Propeller."
Having now described the distinctive properties of the "Curvilinear,"
I will proceed to explain the Figs. in the drawings, and show the
manner in which the same can be formed. The letters in the Figs. of
the drawings represent the same parts and places. Scale, one quarter
of an inch to the foot.
EXPLANATION OF THE DRAWINGS.
Figs. 1, 2, and 3, are sections, and shews the lines and proportions
of the inner curved line "Curvilinear." Figs. 4, and 5, end and side
views of the inner curved line "Curvilinear Propeller." Fig. 6,
angular view of the inner curved line "Curvilinear Propeller," as scen
at the angle of 45°. Fig. 7, plan of the inner curved line "Curvilinear
Propeller. Figs. 8, and 9, end and side views of the outer curved

page_text: The "Curvilinear" is drawn to a scale of five feet six inches perpen-
dicular height from A, to B, Figs. 12, 13, and 14, and the "Curvilinear
Propeller" is twice that height or eleven feet diameter; in all cases the
axis of the "Curvilinear Propeller" must be two elevenths of the
diameter, or nearly. Fig. 1, section of plan;-draw the shaft to any
required diameter; draw G, H, the straight line, and erect the perpen-
dicular W, V; then set off the worm F, A, E, at an angle of 67° to
the shaft; place the lines G, F, and H, E, at the proportional distance
of one quarter of an inch from each side of A, cutting the worm at F,
and E. Fig. 2, is the elevation of Fig. 1. Fig. 3, is the transverse
section;-describe the shaft O, and from the centre of the shaft erect the
perpendicular or centre line A, B, equal to one inch and three eighths,
or five feet six inches; make R, and S, parallel to A, B, with the
distance of G, F, or H. E, Fig. 1; double the perpendicular line A, B,
(see Fig. 15,) and divide it into eleven equal parts; with nine of those
parts as a radius, describe the arc G, F, equal in length to the perpen-
dicular or centre line A, B, Fig. 3; again divide the arc into cleven
equal parts, and with the chord of ten parts G, F, as a distance, apply
it to G, F, and H, E, in Fig. 3, cutting R, and S, in F, and E; upon
the chords G, F, and H, E, erect the perpendiculars M, N, and P, Q;
then with the radius of nine elevenths at M, and Q, describe the arc's
G, F, and H, E; draw the worm F, B, E. Note, if the diameter
of the shaft is required to be greater than that shown in the drawings,
then a lesser portion of the arc G, F, Fig. 15, must be taken. Fig. 13,
end view of the "Curvilinear;" describe the shaft O; then with a radius
of one inch and three eighths describe the circle B, C, D; divide the
circle into sixteen equal parts; find the curved lines G, F, and H, E,
in the same manner as G, F, and H, E, in Fig. 3; then, with a mould,
bend cach succeeding curve on either side of the centre line A, B, so

page_text: that their outer ends intersect the radii of the circle, as shown by the
dotted curved lines; where the outer ends of the curved lines intersect
the radii of the circle draw the worm as represented with C, Z, as a
distance; apply it to A, a, and A, c, in Fig. 1; draw the parallel
lines a, D, and c, C, cutting the worm in D, and C; draw the perpen-
diculars to I, and L, upon the straight line of the shaft, and I, A, or A, L,
will give the distance from each other of the curved lines to form the
"Curvilinear." Figs. 12, and 14, shows the plan and elevation of the
"Curvilinear; draw the shafts O, O, and O, O; divide them into
thirty-two equal parts; draw the ordinates (which are I, D, and L, C,
in Fig. 1,) at right angles to the shaft; let the centre line A, B, be one
inch and three eighths long from the centre of the shaft; then from
the points of intersection in Fig. 13, mark them upon the ordinates of
Figs. 12, and 14, and draw the worms. It is shown the worm has one
revolution each side of the centre line A, B, and although it commences
with an angle of 6710, or any other angle, it has a continually decreasing
angle towards the ends, owing to the disposition of the curved lines,
and the worm would eventually pass into a straight line. Fig. 15, is
the proportionals for the arc, as before described.
There are four varieties of the inner curved line "Curvilinear Pro-
peller," namely the arc, the ellipse, the parabola, and the hyperbola.
The three last-mentioned are formed partly similar to the arc, although
not represented in the drawings; that is to say, for the section Fig. 3,
which represents the arc, the ellipse, parabola, hyperbola, or any other
curved form may be substituted, and which may be found as follows:
after having determined the height of the centre line A, B, Fig. 3, and
finding the distances of the lines G, F, and H, E, from A, Fig. 1, the
line F, E, Fig. 3, will be the conjugate or double ordinate, and
the line A, Z, the half of the transverse diameters or abscissa.
The propellers to be made of metal, or of any other approved material,
to work rotary, and the best position to place them in to work with
power and effect is in a hole in that part of the stern of a vessel known
as the deadwood or rising. The advantages gained by the "Curvilinear
Propeller" above the "Screw Propeller" are these:-First, a non-resist-
ance near the centre of motion, the straight line on the shaft shewing

page_text: the least resistance on its longest axis. Secondly, the "Curvilinear
Propeller" has little or no lateral pressure near the centre of motion;
the curved lines extending gently and progressively from each side of the
centre line A, B, and causing the greatest resistance on its broadest axis,
whereas in the "Screw Propeller" the greater the pitch the greater the
lateral pressure, which combined with the resistance of the spiral line
on the shaft causes a great loss of power from the engine; therefore the
"Curvilinear Propeller" requires less power, or, having the same power
as the "Screw Propeller," would give a greater velocity to the vessel.
Thirdly, owing to the peculiar placing of the curved lines it is evident
that the "Curvilinear Propeller" has a greater amount of propelling
surface than is possible to get from the "Screw" or any other submerged
propeller having the same length of axis, and, consequently, the blades
exert their power with greater effect than any other submerged propeller
whatever.
I do not confine myself to any particular length of the curved lines
in the formation of the "Curvilinears," neither do I confine myself to
two blades in the propellers, as three or four or more might be used,
or to any particular angle or proportions, but that the propellers shall
be of the forn or forms before described.
Having now described my Invention, with the separate and distinct
parts thereof, and the manner in which the same is to be performed,
I therefore claim as new, novel, and original the "Curvilinears" and
the "Curvilinear Propellers" in all their kinds and varieties, at all
angles, and all sections, as described in this specification, for the purpose
of propelling ships.
In witness whereof, I, the said John George Truscott Campbell,
have hereunto set my hand and seal, this Twenty-sixth day of
September, in the year of our Lord 1853.
JOHN GEORGE TRUSCOTT CAMPBELL. (L.S.)