IMPROVEMENTS IN THE MACHINERY FOR PROPELLING VESSELS
Year: 1867

page_text: LETTERS PATENT to Richard Boyman Boyman, of Stockwell Park
Crescent, lately called Park Crescent, in the County of Surrey, for the
Invention of "IMPROVEMENTS IN THE MACHINERY FOR PROPELLING VESSELS
Sealed the, 28th January, 1868, and dated the 1st August 1867.
PROVISIONAL SPECIFICATION left by the said Richard Boyman Boyman
at the Office of the Commissioners of Patents, with his Petition, on the
1st August 1867.
I, RICHARD BOYMAN BOYMAN, of Stockwell Park Crescent, lately called
Park Crescent, in the County. of Surrey, do hereby declare the nature of the
said Invention for IMPROVEMENTS IN THE MACHINERY FOR PROPELLING VESSELS
AND AERIAL CONVEYANCES BY REACTION," to be as follows:-
a screw of two or more threads working in the same horizontal sub-
merged-propelling tubes with divergent ends, with or without expanding and
.contracting valves, as are described in my Patent of the 29th of May 1866,
No.1497,for "Improvements in Propelling Vessels by the Reaction of Water,
[Price 8d.1

page_text: and in the Machinery for the Purpose." No part of my present improvement
is new of itself, but the combination I believe is. I find, for instance, that
William Hale obtained a Patent for this kind of screw, dated the 22nd of
December 1827, No.5594,for "Certain Improvements in Propelling Vessels."
This screw is shown in his Drawing to work in a vertical barrel as a pump at
the stern of a vessel to propel it by the reaction of water; but used in this
way it is economically useless, or it would no doubt be in practice by this time,
being forty years since his Patent. Now a slight difference in form or position
makes a great difference in results in hydro-dynamical propulsion, of which
I consider myself the founder as a science. Though, therefore, I use the
screw in a tube for forcing the water, I do not use it as in his Patent, but
according to the laws, principles, formulæ, and application discovered by me
and enunciated in ny said Patent. Thus by such new combination-of the
screw in my propelling tubes-I make the screwavailable forreactionpropul-
sion in water and in the air. For the latter purpose it has never been applied.
It has been frequently spoken of as the future, propeller of aerial locomotion
in the same way as vessels are now propelled by the screw. But this method
is neither my principle nor application of it. I use the screw in the horizontal
propelling pipes before referred to according to the principles, proper areas,
and proportions contained in my said Patent, and thus propel by reaction
from such tubes, and not by a screw working in the open water or air.
.. I work the screw hydro and aero propeller as follows, which I believe is as
-new as the combination :-For large vessels and aerial machines two or more
cylindrical horizontal propelling tubes with or without contracting and ex-
panding valves, and having divergent ends, will be submerged on each side
beneath or at the stern of the vessel in which such screws will work. A slit
will be cut in the side of the ship and in the side of the tube through which
the connecting rod will pass to work the crank on the screw shaft, which will
turn in proper bearings at each end. With two or more screwhydro-propellers
a crank shaft will run on each side of the ship, and by means of a pair of
engineswork such screw hydro-propellers. To prevent thewater from getting
into the ship, and also for the purpose of converting it into a sailing vessel,
and of repairing the hydro-propellers, a case will be fitted to the side large
enough to hold each tube when drawn into it. Through a stuffing box in this
case an elongated piston rod will pass and work the connecting rod of the
screw bydro-propeller. This may also be worked by wheelwork, the wheel
round the hydro-propeller protruding through the side of the pipe and vessel,
and being connected with the wheel on the shaft of the engine in a box to
prevent water getting into the ship. The connecting rod and crank to work

page_text: the hydro-propeller can be made to work free from water. Lengthen the
propeller shaft sufficiently to leave a clear entrance for the water into the
propelling tube; let the shaft pass through a stuffing box into a double cone at
the side of the ship sloped off to lessen the resistance; make a communication
from the inside into the cone, and work the crank of the propeller shaft inside
such cone.
The hydro-propellers, being first disconnected, will be run in and out of
their cases on rails and wheels like a ship's gun, and be worked by a piston
rod through a stuffing box in the case by screw or wheelwork, or donkey
engines. When the propellers are in their cases a slide. will cut off commu-
nication with the external water. Something very similar to this arrangement
for moving the propellers in and out of the ship is already contained in my
Patent of the 12th of December 1866, No. 3262, for "Improvements in
Applying Jets of Steam by Action and Reaction to Propel Vessels and Aerial
Conveyances, with other Improvements in the latter, and in the Machinery
for both, Parts of which are applicable for other Hydro and Aero Purposes."
My other improvement in the machinery for reaction propulsion is in the
hydro and aëro propeller contained in my said Patent of last year, No. 3262.
It is in making the floats hollow to permit a free exit of the water which
enters the slits in the drum when the floats are drawn out for reaction. For
I find that without such hollow floats the water would be'squeezed out between
the floats and surface of the slits when the floats are drawn in. This would
wastea good deal of power unless the slits in the ends of the drum were made.
wide enough for the water to get out there easily, but this would entail loss
from leakage.
SPECIFICATION in pursuance of the conditions of the Letters Patent, filed
by the said Richard Boyman Boyman in the Great Seal Patent Office
on the 31st January 1868.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, RICHARD
BOYMAN BOYMAN, of Stockwell Park Crescent, lately called Park Crescent,
in the County of Surrey, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her Letters
Patent, bearing date the 1st day of August, 1867, in the 31st year of Her
reign, did, for Herself, Her heirs and successors, give and grant unto me,
the said Richard Boyman Boyman, Her special license that I, the said
Richard Boyman Boyman, my.executors, administrators, and assigns, or such
others as I, the said Richard-Boyman Boyman, my executors, administrators,

page_text: 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, 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 "IMPROVEMENTS IN THE MACHINERY FOR PROPELLING VESSELS AND
AERIAL CONVEYANCES BY REACTION," upon the condition, amongst others, that I,
the said Richard Boyman Boyman, by an instrument 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 performed, and cause the same to be
filed in the Great Seal Patent Office within six calendar mouths next and
immediately after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Richard Boyman Boyman, 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, that is to say :-
DESCRIPTION OF MACHINERY, SHEET I.
Fig. I. is a side clevation of a steamer and of 2 screw hydro-propellers
working in my submerged cylindrical propelling tube with divergent entrance
and exit; Fig. 2 is a half vertical section of the same; Fig. 3 is a half plan;
Figs. 4 and 5 show a front and end elevation of a two-threaded screw
hydro propeller and tube with part of the tube and frame removed; and
Figs, 6 and 7 show the driving discs enlarged for disconnecting the hydro-
propellers. The same letters refer to the same parts in all the Figures in this
Sheet I.
The screw hydro-propellers shown in Figures 1, 2, and 3 are four-threaded,
whose length is about one-fourth of the pitch, and propel the vessel by the re-
action of the water they drawin in the opposite direction to its entrance. The
vessel is backed by reversing the engines and hydro-propellers, of which there
are two on each side of the vessel for large steamers. Each pair can be driven
by two or three engines, so that by reversing only one set of engines the
steamer can be turned or manoeuvred with greater facility than at present.
The shaft for three engines for each pair of hydro-propellers is shown in the
Drawing, that if one engine break down the others may still propel.
The screw hydro-propellers are connected and worked in the following
manner-They have round them a toothed wheel J, which fits into a driving
wheel K solid or connected by arms of larger diameter than the propellers in
proportion to thenumber of revolutions required. These wheels are kept in
gear by the frameab, part of which, marked a, forms the cylindrical propelling

page_text: pipe round the screw hydro-propeller, which pipe is connected by Knie-edged
arins g both at entrance and exit. In the middle of these arms are formed
the bearings h, in which the shaft i of the hydro-propeller j revolves. Part
of the cylinder a and side of the vessel is cut away to allow the driving wheel k
to fit into the toothed wheel round the hydro-propeller, as shown in the
Drawings. The driving wheel k is fixed on the shaft l, and revolves in the
Towards each end of
bearing m formed in the part of the frame marked b.
For
the driving shaft q is fixed a disc or crank wheel n, in which is fixed the crank
pin o, which fits into the slot in the driving disc p fixed on the driving shaft q.
This passes through the water stuffing box r, and is driven by the engines.
The object of this arrangement is to enable the screw hydro-propeller to.
be disconnected from the shaft that they may be drawn into the water-tight
cases d to be repaired or to convert the steamer into a sailing vessel.
this purpose the engines must be stopped in such a position that the pin o and
slot in the discs n and p point towards the centre of the ship; a position.
which may be known.by marks on the shaft and stuffing box, or other means...
A groove Sis formed in the water-tight case d to receive the pin o when the
hydro-propeller is drawn into its case d, which groove acts as a guide and;
insures the pin o falling into the slot in the disk p when it is desired to put
the hydro-propellers into gear, again.
The water-tight cases d are made in two parts and fixed to the side of the
ship, each large enough to take in the. hydro-propellers with the reaction
propelling tube they work in and, the driving wheel k.
The.frame which
i
joins these together, ab, runs on rails on friction wheels c at each side in the
water case d, and the whole is moved in and out by means of the screws and.
gearing e.. When the hydro-propellers are drawn in the openings in the
ship's side are closed by the large sliding door fmoved by the ratchet wheels.
The nuts (not
and handles shown in Fig. 3, or. by other suitable means.
shown in the Drawings, which connect the flanches of the water-tight case
shown by the line in the middle of the case, Fig. 2, can then be unscrewed,
when the top can be removed and the hydro-propellers got at. The case which
receives the driving wheel k is not so wide as the case which receives the
screw hydro-propellers and their reaction propelling pipes.
.
The Drawings in Sheet I. are for a vessel of about the size of the Minotaur
ironside, and the number of revolutions of hydro-propellers and engines may
be thus found:-Leth the number of revolutions of the hydro-propellers,
here 6 feet diameter, e that of the engines, m the mean velocity of hydro-
propellers in one, revolution, the velocity of entering water for reaction, and
a the diameter of driving wheel, which is here twice the diameter of the hydro-
.

page_text: 30-8
=== 3.3 per second; and
60=ex 60=99, the number of revolutions of engines
per minute, which can be reduced by making w 2.5 or 3 times the
diameter of the hydro-propellers. The area of the 4 propeller pipes is
4 X (62 x 7854)=113:0976 square feet.
be, by my formula herein-after given, R
113.097 (30-3-23-632)=49938, say 50,000 lbs. The nett horse
R{+5(V)} 50000 { 23-032 + *5 × (30-8 – 23-632) }
2174 x 20
The resistance overcome will
2 Va (V-v) ==== 2 × 30.8 X
550
power required for this will be, 550
=2474 EP. To this add 20 per cent. for the losses of my system of
6185 EP, and w
'we get (2474 + 618.5=)
3092-5 ; to which we must add 20 per cent. for engine and shaft
773-125, making the indicated IP required
hydro-propulsion
3092-5 x 20
friction =100-20
100-20-
(=3092-5+773 125 =) 3865 625..
By my system of hydro-propulsion the screw hydro-propellers will be
submerged as much as the present screw propellers. How far, therefore, such
hydro-propellers when placed at the side will work in the body of water set
in forward motion by the ship I cannot say, because it is not known to what
distance on each side such forward motion of the water extends; but it is
found that when the screw of a very large vessel works in such forward body
of water at the stern there is some if not a considerable saving in power. In
such case my hydro-propellers and pipes with divergent entrance and exit can
be placed at the stern, one on each side of the rudder, like twin screws, and
be worked in the same way as twin screws. But the propellers will still
be screw hydro-propellers on my system,propelling the ship by direct reaction,
pursuant to the laws, principles, and formulæ discovered by me, as mentioned
in my Provisional Specification. They will not be therefore ordinary screw
propellers propelling the ship by impulse and indirect reaction, as is now done
both by screws and paddle wheels.
The same description, the same application, and the same remarks as in
the last paragraph are applicable to these screw bydro-propellers when used
as aëro-propellers to propel aerial ships or conveyances by the direct reaction
of air; but for aerial navigation a much higher velocity of the propelling
fluid is required than for water navigation. To get this with a lower velocity
+

page_text: of aero-propeller my expanding and contracting valves, referred to in the
Provisional Specification, will be required. These are explained in my Letters
Patent of the 29th of May 1866, No. 1497, p. 8, line 20 to p. 9, line 18;
p. 44, line 5 to p. 45, line 15; and same page. line 26 to. 38. It seems
scarcely necessary to observe that in aerial navigation we do not want cases
to receive the screw aero-propellers and driving wheels, consequently do not
want any of their moving machinery.
I may here observe, what otherwise cannot be known, that I thus realize at
last, both for water and aerial navigation, that which I predicted 19 years ago,
namely, in my paper on the Philosophy of Mechanical Propulsion, written in
August 1849, where I said,-"The true principle of propulsion is to make
"the element of resistance the medium of overcoming it, an action that can
"only be obtained economically by unbalanced pressure or reaction." Now
this principle of mechanical propulsion is in direct opposition to the principle
of natural propulsion seen in fish and birds, and in the screw and paddle
wheel. For in all these cases propulsion is obtained byindirect reaction, which
is by the impulse of a solid upon a fluid; whereas I obtain propulsion by the
direct reaction of a fluid upon a solid, using for this purpose the medium of
resistance, water, in the case of vessels, and the medium of resistance, air, iu
the case of aerial machines to overcome such resistance. Natural propulsion,
seen in the screw and paddle wheel,embodies the Baconian philosophy,in his
Valerius Terminus or Interpretation of Nature, "There is no proceeding in
"invention of knowledge save by similtude." Mechanical propulsion,
reaction, embodies my own philosophy "the laws, but not the imitation of
"nature."
$*
This principle also fulfils my other prediction contained in my letter to the
Reverend Professor Airey, A.M., on the 5th of March 1851, first published
in my Specification of 1869, No. 1155, p. 14, line 5,-"I am convinced, for
masyreasons too numerous to trouble you with,that the principle of reaction
"will be the only method of propulsion on water and in the air, and will
never be superseded." Now there is no presumption in the positivism of
science based on the primary laws of nature; for these are the ultimate
development and reach of human intellect, beyond which man cannot go. In
the stately apothegm of Bacon,the foundation of our dominion over nature,-
"Homo nature minister et interpres, tantum facit et intelligit, quantum
"de naturæ ordine re vel mente observaverit nec amplius scit aut potest."
Why therefore reaction will never be superseded for propulsion in air and
water is because there are only two principles of propulsion possible to man;
impulse, shown in the paddle wheel and screw, fish and birds; and reaction,

page_text: shown in the issue of water, as in my system of hydro-propulsion; since
therefore man must choose one or the other he will naturally choose that
which is the most economical and convenient application of power. That this
is reaction I will now show.
THE LOSS OF PRIMARY VELOCITY AND CONSEQUENT SMALL EFFICIENCY OF THE
PADDLE WHEEL AND SCREW.
The saving in fuel and in area of application by reaction propulsion.
depends on the truth of my discovery in April 1866 of the loss of primary
velocity in the paddle wheel and screw equal about 50 per cent. of the power
expended upon them; it is this loss which makes the efficiency of the paddle
wheel and screw so small. The particulars of this discovery will be seen in
my Specification of the 29th of May 1866, No. 1497, pp. 6, 7, 30, 31, 32.
It will also be seen therein (at p. 32, line 24 to p. 35, line 31,) that the only
formula at variance with such discover yis that of the eminent Professor W.I.
Macquorn Rankine, the first European authority on such matters, who makes
the resistance of vessels R=fv2 S.lbs. Myreasons for venturing to think that
there must be some error in this formula will be found in mysaid Specification
of 1866, p. 34, line 24 to 37; p. 51, line 37 to line 5, page 52; same page, line
22 to p. 53, line 21; and at p. 68 to the end of page 69. It will also be seen
at p. 1 of my Provisional Specification of 1866 that "The saving of more
"than one-third of the fuel consumed in paddle wheel and screw propulsion,
besides the proportionate cost and weight of engines, boilers, water,and pro-
pellers . . . . . cannot be made if Professor Rankine's formula, R=f v² S,
"is the true one, and my application of the law of fluid impulse to the paddle
"wheel and screw is unsound." Specification, p. 40, line 6 to 10.
"
It is therefore proper to observe that my patience in seeking for the law
which governs the frictional resistance of vessels was rewarded in October
last (1867), when I discovered that the frictional resistance of vessels is not
proportional to the immersion and surface S, as assumed in Professor
Rankine's formula, f² S, but that the resistance is always less than the
actual surface in contact with the water. Taking the Nautilus, Volunteer,
Waterwitch, Vixen, Viper, Banshee, Bellerophon, and Warrior as guides, I
found that the actual resistance of vessels is about two-sevenths less than the
resistance due to the whole immersed surface S. Whether or no these eight
vessels are a sufficient number of instances from which to deduce a general
law of frictional resistance I cannot say, but they are of the following different
lengths-115, 162, 189, 300, and 380 feet. In all these I found a sufficient
approximation to a decrease of resistance of two-sevenths to indicate that

page_text: unity of principle which runs through all nature, however diversified her
operations.
I have, never met with any empirical formula more reasonable than
Professor Rankine's, R=f 2 S lbs. because his coefficient f= 01, multiplied
by,1-1 for the augmented surface, is deduced from the experiments of the
three first experimental philosophers of three nations, Beaufoy of England.
Morin of France, and Weisbach of Germany, because also the frictional
esistance of water encreases as the surface S in every other known case, the
flow of water in pipes, for instance. It will however be seen by the following
extract from Beaufoy's great work, "Nautical and Hydraulic Experiments,"
preface, p. XXIV., that a resistance in the direct ratio of the immersed
surface S is not true in the case of vessels :-"Among the conclusions
"suggested by the tables, one of the most curious is that the increasing the
"length of a solid of almost any form by the addition of a cylinder in the
"middle exceedingly diminishes the resistance with which it moves provided
"the weight in water continue to be the same. A fact I apprehend that
"cannot be easily explained." No; but the law was at once revealed to me,
for by induction the resistance of vessels is not directly as the immersed
surface embodied in the formula, R=fv S, but inversely as the length of
surface in certain proportions. I have however found that this singular law
does not depend, as Beaufoy says it does, on the weight of the body in water
continuing the same, provided the greater weight proceed from the greater
length. It is remarkable that his work should have been in the hands of
somanynaval architects, engineers, andscientificmathematicians investigating
the resistance of vessels, and that so unaccountablean experiment should either
have escaped notice, or that an erroneous law should have been deduced from it.
We see in this law of decreasing resistance another departure, for some
wise purpose, from the ordinary laws of nature, like freezing water and latent
heat: For it is plain that as we increase the surface moving in a fluid we
must increase frictional resistance and retardation, and so we do. This fact is.
found in water flowing through pipes, the knowledge of which forms one of
the fundamental principles of my system of hydro-propulsion. But in vessels
passing through water it is and it is not so. For by increasing the surface
n length in certain proportions some strange law comes into operation and
not merely neutralizes the ordinary law of friction and resistance due to
such increased.surface and to the square of its velocity, but actually makes
he-resistance of the whole..mass less than it was before, "exceedingly
'diminishes the resistance with which it moves."-Thisis themystery, especially

page_text: as such reduced frictional resistance makes the dynamical resistance of
vessels about the same as my discovery in April 1866 (of the loss of primary
velocity in the paddle wheel and screw) makes the resistance. Such discovery,
therefore, is at last confirmed by the law of reduced frictional resistance so
discovered in October last by induction from Beaufoy's experiments; and
it justifies the confidence I placed in the uniformity of the laws of nature in
my Specification of May 1866, No. 1497, and particularly at p. 51, line 37
to p. 52, line 4, from which I may be allowed to extract these words, "I
"have faith in principles which have never yet misled me." Further at
p. 33, line 23, I refer to Professor Rankine's frictional formula, f v2 S,
contradicting my discovery of the law of fluid impulse, and consequent loss
of primary velocity against a plane of the same area as the fluid, in these
words, "In all contradictions of science we must prefer the laws of nature
"to those of man, I cannot then think that there is any contradiction of the
"laws of nature." But for this reliance on the uniformity of such laws,
and that the same results must take place as well when a plane moves against
a fluid as when a fluid moves against a plane of the same area, I should most
likely have abandoned hydro-propulsion last year, on the authority of one so
distinguished in science as Professor Rankine, because my acquaintance with
his works has taught me to respect any formula of his.
66
How positively this was against my discovery of the loss of primary velocity
in the paddle wheel and screw will be best seen by the following extract
from the Professor's paper of the 27th September 1862, No. 136-"This
"formula has been used to calculate approximately the resistance of steam
"vessels, and itз results have been found to agree very closely with those of
"experiment, and have also been used since 1858 by Mr. James R. Napier
"(the eminent shipbuilder and engineer), and the author with complete
"success in practice, to calculate beforehand the engine power required to
propel proposed vessels at given speeds." Now when practice confirms
theory, fonnded on experiments of the first scientific authorities, we have the
highest evidence of truth, except the laws of physics. For, as Galileo justly
remarks, "When we have the decrees of nature authority goes for nothing,
"reason is absolute." We see, however, by the statement of Professor
Rankine how entirely new is my discovery of the loss of primary velocity and
the small efficiency of the paddle wheel and screw, and that the resistance of
vessels is much less than is believed, because not knowing these things no such
loss is allowed for in the Professor's formula. Thus part of the engine power,
which is there considered to go in overcoming the resistance, is expended in

page_text: making good the loss of primary velocity, and the consequent deficient
propelling power of the paddle wheel and screw.
We have now, however, reconciled for the first time the law of frictional
resistance of vessels with the dynamic law of fluid impulse against a plane of
the same area. For I have found by calculating the reduced frictional
resistance of the eight vessels referred to that were they propelled by vertical
paddle wheels both laws, frictional and dynamic, would make the resistance
sufficiently near for such gross practical purposes as steam navigation, where
minute accuracy is not required, I have therefore framed formulæ for this
purpose, and reduced the first two to their ultimate expression of simplicity
by eliminating g=32-2, 2g=2x 32.2, and w=64 lbs.
FORMULE FOR THE RESISTANCE OF VESSELS.
Paddle wheel formula R7381 Va (V-v) lbs.
Hydro-propulsion,,
Frictional
RV + (V-v) a = 2 Va (V-v) lbs.
2
R
CX008 v² S
lbs.
V is the mean velocity of the paddle wheel and of the feed water of hydro-
propulsion; a, the actual area of both; v, the velocity of vessel; C, a variable
coefficient which measures the decreased resistance of the vessel due to
its encreased length according to Beaufoy's experiment before given. The
variable value of this coefficient I cannot of course determine, it may vary.
from 80 to 99. S is the immersed surface in square feet. No great reliance
however can be placed on this formula because it is empirical and not dynamic
like the first two, which are absolutely certain. The hydro-propulsion formula
is not merely the best of the three, but the best possible for all time, because
it is based on the primary laws of nature, reaction; and the issue of water is
governed by the laws of force and motion deduced from gravitation.
Consequently this formula is the ultimate reach of science for finding the
resistance of all vessels of whatever size or form.
Those who may suppose that these and similar principles enunciated in my
former Specifications of 1860, No. 1155; of May 1866, No. 1497; aud
December 1866, No. 3262, are more suitable for a treatise than for a
Specification do err, I think, as not knowing science and its requirements..
For in the first place all science should be made clear to the meanest capacity
and not hidden in the convenient obscurity of mathematics. And, secondly,
according to the method of the Creator must be the method of science; the
laws first, the application afterwards, for such is the order of nature. Besides
it is only as we understand the laws of nature that we can understand their
application; why this way instead of that? Now the improvement of steam.

page_text: navigation, of naval architecture, and thevalueof mysystemofhydro-propulsion
all depend on knowing the resistance of vessels and the law of fluid impulse.
And the importance of this kuowledge will be seen by the following facts:-
Some of the first experimental philosophers of most civilized nations have
tried to determine the resistance of vessels, but unsuccessfully. Among them
are Condorcet, D'Alembert, Du Buat, Borda, Franklin, Hutton, Bessel,
Thibault, Beaufoy, Lagerhjelm, Morin, and Weisbach. Beaufoy says in his
"Nautical and Hydraulic Experiments," preface, p. XXXII,-"The united
"experiments made by the English and Swedish philosophers have not cost
"so little as 50,000l." Yet so uncertain still are the data for finding the
resistance of vessels that the British Association for the Advancement of
Science appointed three or four years ago a committee to try more experiments
on this subject, of which Professor Rankine was one. We have, however,
shown that the formula of even this distinguished man for the resistance of
vessels, Rf v² 8, is erroneous, concealing as it does the important law of
physics, the loss of 50 per cent. of the force of fluid impulse against a plane
of the same area. Further, "Again and again," says Admiral Moorsom, in a
paper read at the Meeting of the British Association in 1860,-" Again and
again have the Steam Ship Performance Committee pressed upon successive
"First Lords of the Admiralty the great value to the public service which
"must ensue to determine by specific experiments the resistance under certain
"conditions of certain vessels as types ... Modifications of form have
"been arrived at by a long painstaking tentative process, and we are still
'following the same tedious process in order to establish new rules for the
"application of steam power." Herschel also in his Natural Philosophy,.
p. 179, paragraph 188, refers to "the almost insuperable difficulties
"connected with the motion of fluids," and at p. 236 observes "that the
"knowledge of the resistance of fluids to bodies moving in them is of great
importance to naval architecture."
"
If, however, this knowledge is of so much importance in naval architecture,
it is everything to me, for the value of (1867-1842 =)25 years' philosophical
pursuits depends entirely on this question of resistance and law of fluid
impulse, and on nothing else; because the want of this knowledge induced me
to abandon hydro-propulsion in 1867, with many years of thought, labour, and
expense, for the reasons explained in my Specification of 1866, No. 1497, p. 3.
Such want, moreover, has retarded the improvement of steam navigation for
half a century or more, because had the real resistance of vessels been known
the loss of primary velocity in paddle wheel and screw propulsion would also
have been known, hence the superiority of reaction propulsion would have

page_text: 5
been discovered long ago, and millions of money saved in England's most
precious commodity, coal. For the first step to improvement is to know
existing defects; thus it was that not knowing the defects of the paddle
wheel and screw in 1857 I abandoned for nine years the true principle of
propulsion, reaction, for ocean and aerial navigation, and only returned to it
again in April 1866, when I first discovered the great loss of the paddle wheel
and screw, as shown in my Specification of that year, No. 1497, pp. 6,7, and 30.
Having thus shown by so many authorities the general importance of
knowing the resistance of vessels, and the real efficiency of the paddle wheel
and screw as propelling instruments, and the especial importance of such
knowledge to myself, as the foundation of my Inventions and Patents, I think
it right to put on record in this my Specification that these problems in
physical science are at last solved. It is the more necessary to show this
fact, because it will be seen by my Patents of May 1866 and December 1866,
that I was there feeling my way in the matter of resistance, greatly perplexed
by Professor Rankine's formula, which contradicted by actual experiment
my discovery in 1866 of the small efficiency of the paddle wheel and screw,
consequently the whole value of the thought and labours of (1867-1842=)
years, and of the Inventions contained in my three Patents of 1866 and
1867, depend on what really is the resistance of vessels found by the normal
modulus of efficiency of the paddle wheel and screw. This being at length
settled by the law of decreasing frictional resistance confirming the dynamic
law of fluid impulse against a plane of the same area, I can now give for the
first time in steam navigation science the true measure of the resistance of all
vessels driven by vertical paddle wheels.
25
For simplicity I have eliminat ed g=322; 2g=2x32.2; and w=64 lbs. ;
and allowed 20 per cent. for engine friction, hence the actual propelling power
of the floats and, consequent resistance R, useful effect U, loss L, and
power expended P, will be found by the following,―
PADDLE WHEEL FORMULE PURSUANT TO THE LAW OF FLUID IMPULSE.
R7381 Va (V-v)
U=7381 Vav (V-v)=R v
L=R7381 (V)2 Va=R+R (V-v)=R V
P=7381 (V2) V a=2 R (v + 2) = R(V + v)
feet
"
"
lbs.
"
37
Now the useful effect U and loss L must equal the power expended P,
therefore RvRV = R(V+v) the proof required. To find the indicated
20 nor nont for engine friction must be added to P, for on this

page_text: cally the same as my paddle wheel formulæ discovered in 1857, and published
in my Specification of 1860, No. 1155, p. 17. And it was in consequence of
such formulæ that I abandoned hydro-propulsion in 1857, as stated in such
Specification, pp. 14, 16, 17. I have here. only modified such formulæ
pursuant to the law of fluid impulse and small efficiency of the paddle wheel
and screw discovered by me in April 1866, as before mentioned. This
discovery now enables me to show the superior economy of the principle of
reaction to impulse for propulsion by the

page_text: which also is the true formula for the undershot water wheel. Thus it is that
the only dynamic formula, pure and simple, is for hydro-propulsion,
R-2 Va (V-v) lbs.
Because the principle of reaction is not governed by the law of fluid impulse
like the three other transmitters of water power. The superior economy of
reaction for water and aerial navigation is therefore now made manifest for
the first time. For the formula for power expended P on paddle wheel, screw,
and hydro-propulsion is the same for all, as shown in the formulæ ; though for
the undershot it is considerably more, for reasons which we need not here
enter into. Whilst, however, the formula for the power expended is the same
in the three methods of propulsion specified, the loss is very different. In the
paddle wheel and screw, L is as much as R v+R (V-v), in consequence of
the loss of primary as well as residuary velocity, but in hydro-propulsion the
loss is only (V-v) Va= R() because there is no such loss of primary
but only of residuary velocity, as shown in the formulæ. I have said that it
was for different applications of such discovery of the loss of primary velocity
embodied in these formulæ that I obtained two Patents, one in May 1866.
and one in December 1866, and it is for auother application, a screw hydro-
propeller and machinery connected therewith, that I obtained the third Patent
on the First of August 1867, which I am now specifying; but however co-
fident I expressed myself in my first two Patents of the truth of such discovery,
and of the consequent superiority of reaction to impulse for propulsion through
air and water, I was unable to establish the fact until recently. This I can
now do by the Adiniralty official returns of the competitive trials of the following
vessels. taken from the Times of the 15th of August last.
The Waterwitch however did something better on previous trials; I think
therefore it is fairer to take her best performance for comparison with my
system of hydro-propulsion. I have accordingly done so in the following
analysis of the Nautilus and Waterwitch, both propelled by Ruthven's internal
indirect application of hydro-propulsion. The data a, V, v, and IH P, are

page_text: taken from the Admiralty official returns, published in "The Engineer" and
Engineering," and from private inquiry :—
a is the area of reaction in square feet; V, the mean velocity of the propeller
floats in feet per second; v, the velocity of vessel; S, the residuary velocity in;
horse power; R, the resistance of the vessel in lbs. at the speed v; U, the
useful effect in horse power; IH P, the indicated horse power; and L, the
whole loss, including loss of application, engine friction, and residuary velocity.
The speed of the "Nautilus" was 8.3 knots=1.688 x 8.3=14 feet per
second; and the speed of the "Waterwitch" was 9-5 knots=1.688x9.5=16
feet.. per second.
Resolving these results into their components, we get, the modulus of
efficiency of Ruthven's plan of hydro-propulsion as follows:-
True science disdains uncertainty and abhors waste; but without law there
is no certainty in application or results, and no economy; with law no
uncertainty and no waste. The Nautilus, made for speed, is, like her name,
a mere shell, drawing only 2 feet of water, and if only 91-5 indicated
power: The Waterwitch is not made for speed, is one of Her Majesty's
ironsides may they, like the heroicand glorious Cromwell's,never knowdefeat
-draws 11 feet of water, and is 800 indicated power. Yet both being contrary
to the principles of hydraulics and hydro-dynamics, the loss of application is
scientifically the same, for we may say of science, as it is said of law, de
minimus non curat scientia. Here the difference is small enough, the loss in
application showing a difference of only (53-815-51-) 2.815 per cent.; small
indeed for so great a difference in the size and horse power of the two

page_text: We have now reliable data, for the first time since the introduction of
steam navigation, to compare, 1st, the principle of reaction with that of
impulse of a plane against water, shown in the Volunteer paddle wheel and in
the Vixen and Viper twin screw steamers; and 2nd, to compare the right
principle of reaction, as shown in my system of hydro-propulsion, with the.
wrong principle, which is internal indirect acting, as shown in the Nautilus
and Waterwitch, adopted by the Lords of the Admiralty and deemned the best
application of hydro-propulsion. It was said in "the Engineer" of the 30th
of September last, that the Vixen and Viper were designed by the Chief Con-
etructor of the Navy for the purpose of comparison with the Waterwitch to
try that principle of propulsion, and that these three vessels have practically,
the same horse power, length of keel, and displacement. But even if they
had not, and were not of the same type, still if vessels go at about the same
speed with about the saine power as these did, their resistance must necessarily.
be about the same. We may therefore safely take the resistance of the Viper
and Vixen at that found for the Waterwitch at the same speed. This is
5009 lbs., as shown in the fifth column of the analysis before given. The
velocity of the vessel » being 9-5 knots, v=1688 x 9.5= 16 feet a second.
We will take the velocity of propelling water V for my system at 1-6 times,
v=16 x 16 25-6 feet a second. Therefore the area of reaction required to
propel the Waterwitch, Viper, and Vixen will be,
R=Va (V-v)=5010 lbs. =2x25-6 X (25.6-16) × a
5010
5010
a=2)=2x256 x (256-16)=10-2 square feet nearly.
Hence the area on each side of the vessel will be 10
the diameter of.each propelling reaction pipe d
fore the power required will be
=
5.1 square feet, and
==
7864
= 2-6 feet. There-
=
- Va
550
= 190
25-6-16 x 256 × 102
550
nearly, to which we must add the losses of my systein, and then the engine
triction, to find the gross indicated power required. The following are my
losses: 1. From the coefficient of influx of the propelling water into the pro-
pelling pipe. 2. From friction of the water in the straight part of it. 3 From
the change of motion of the water therein. 4. From leakage. And, 5, from the
reactionary pressure against the hydro-propeller axle and bearings. Too

page_text: many pages of figures would be required to give the different formulæ, and
tedious calculations of all these, but the result is, that the gross losses of my
system of hydro-propulsion will not exceed 25 per cent. This is the amount
already calculated in my Specification of 1866, No. 1497, p. 39 I think,
however, that the propelling pipe may be shortened and the divergent entrance
enlarged so as to reduce the losses to 20 per cent. We will therefore add 20
per cent. to the nett horse power = 100 × 20 = 475 EP, making 190 + 47.5 =
2375 EP. To this we must add 20 per cent. for engine friction, =37.5 × 200
327.5 x 20
60 EP nearly, and thus we get the gross indicated horse power required to
propel the Waterwitch, Vixen, and Viper by my system; namely, 237+ 60 =
297-5. But for practical contingencies we will say 350 FP.
800-350 x 100
x
657-71 350 x 100
350
=
We have seen by the Admiralty official returns that the indicated horse
power of the Viper was 651-6, and of the Vixen 657.71. The Waterwitch
was 773-13 at 9-223 knots, but at the higher speed of 9.5 knots 800 EP.
Therefore the saving by my system of hydro-propulsion would be 651-6 - 350 x 100
= 86 per cent. on the Viper, 350
87.9 per cent. on the Vixen,
twin screws, and 350 128.5 per cent. on the hydro-propelled Water-
witch. So far as regards the principle of impulse in screw vessels. As
regards the same principle in paddle wheel vessels we will take the resistance
of the Volunteer, engined by Messrs. Penn, at that found for the Nautilus, as
they both went at about the same speed with about the same power. The
resistance being 724 lbs. at8-3 knots, as before shown, = 1:688 x 8.3 = 14
feet, a second. Let the velocity of propelling water V-16=16 x 14 =
22-4 feet a second. The area of reaction required to overcome the resistance
will be nearly 2 square feet, and the gross indicated power (including 20 per
cent. for my losses and 20 per cent. for engine friction) will be 40 nearly, but
for contingencies say 50 EP. Now the indicated power of the Nautilus and
Volunteer given by the Admiralty officials on the trial of these vessels was
91. Therefore saving by my system 91-5-50 x 100
83 per cent. on the radial
paddle wheel.
50
-
We now see on a sufficient large scale to go by the much greater economy
of the principle of reaction-than of impulse. I venture to think, therefore,
that the discovery of a principle of propulsion which will save so largely in
coal, the most precious commodity of England and the world, is an important;
discovery in steam navigation, where saving of weight of fuel, engines, and
boilers is more needed than on land, especially as the principle of reaction will
never be superseded, as predicted in 1851, for the reasons before given. The

page_text: princile of reaction, however, is of even greater importance for aerial
navigation, because for those light and boundless realms we most require
to reduce the weight of fuel, engines, boilers, and water to a minimum.
Now the doctrine here enunciated is, that the great principle of propulsion
reaction was expressly designed the Creator for the exclusive use of man
to navigate the heavens and the ocean, being denied to the creatures of both
elements, the fowl of the air and the fish of the sea, for their principle of pro-
pulsion is that of impulse, like the paddle wheel and screw. It is true that
all these are propelled by the reaction of the fluid they set in motion, but this
is indirect reaction by the impulse of a solid against a fluid; not, as in hydro
and aero propulsion, direct reaction by the simple issue of a fluid from a solid
nto the air or water. For this principle makes the element of resistance the
medium of overcoming it, which is the philosophy of mechanical propulsion
enunciated in my paper of August 1859, and not natural propulsion.
In my Specification of May 1866, pp. 6, 7, and 30, I have shown that the
superiority of reaction over impulsewas discovered in April, 1866, by induction
from experiments with a minute jet of steam (1866-1842) 24 years before,
a Drawing of which is given in such Specification,Sheet 1, and therein called
"Reaction and Impulse, 1842." Now the greatest discoveries can only be
made by the greatest methods, induction and deduction, that high mental
calculus which far transcends the mathematical, being of much higher reach
and of larger scope, less confined too than experimental science, the lowest,
meanest, least intellectual grade of all. Thus it is that the greatest discoveries,
from Copernicus and Columbus to Newton and Watt, have all been made by
inductive philosophy. Now I have shown in my Specifications of 1860, No.
1155, p. 14, line 25, and pp. 16 and 17, also of 1866, No. 1497, p. 3 and 32,
and of 1866, No. 3262, p. 73, and elsewhere, and also in my present Specifi-
cation, that all the experiments of Professors Woolhouse, Barlow, and others
with steam vessels and models failed to discover the loss of primary velocity
and the true laws of paddle wheel propulsion; that all the experiments of
D'Alembert, Beaufoy, and others failed to discover the true measure of the
resistance of vessels; and that all the experiments on aerostation based on the
Baconian aphorism" There is no proceeding in invention save by similitude,"
have failed to discover the true principle of aero-propulsion. It is therefore
difficult to see how the principle of reaction for these purposes could have
been discovered, except by abstract experiments similar to those in 1842, by
nduction from them of those general laws which entail a loss of 50 per cent.
n every case of plane and fluid impulse of the same area, and from such law
of loss the greater economy of power in reaction; also the greater convenience.

page_text: Theoretical efficiency for propulsion
Indicated power
-
100
"
-
A loss of primary velocity of only 35 per cent. seems to contradict what
has been said in my Specification of May 1866, p. 30. line 20 to line 10,
p. 31. It is there observed that when a fluid impinges against a plane of
the same area the loss of impulsive force is 50 per cent. of the power expended,
and such is the fact. The power lost is always equal to the power imparted,
let the power be 100, half of it is imparted to the plane, and the other half
is lost, and this is a loss of (100-50 x 100 =) 50 per cent. ; but with a steam
engine instead of a fluid 20 per cent. of the indicated power is consumed in
friction, and 10 per cent. in residuary velocity, equal 30 per cent. This
leaves only (100-30 ) 70 per cent. of primary power to be expended on
the floats, half of which is by the law of fluid impulse imparted to them, and.
half lost. Since, therefore, the primary power is here only 70, and this
loses 35; the loss of primary velocity-70-36×100-50 per cent. here also, as in
the impulse of a fluid.
paper on
But theoretical efficiency is never obtained in practice, especially in
paddle wheel and screw vessels at sea, because subject to ceaseless shocks
and varying immersion. Now, judging by Mr. Froude's admirable
the screw, and by calculation of the performances of vessels, we may
consider that about 10 per cent. of the 35 imparted to the propellers is not
transmitted to the ship, but is dissipated in shock, irregularity of action, and
driving the water in other directions than exactly horizontal, as is done in
reaction, where every drop must be sent in a straight line. Hence we get the

page_text: PRACTICAL EFFICIENCY OF THE PADDLE WHEEL AND SCREW, PURSUANT TO
THE LAW OF FLUID IMPULSE, AS FOLLOWS:
Engine and shaft friction
Loss from primary velocity
Loss from shock, &c.
,,,residuary velocity
"Practical efficiency for propulsion
Indicated power
20 per cent..
-
35
"
. .10.
-
10
25
100
Now the Volunteer paddle wheel and Vixen and Viper twin screws more
than confirm so small an efficiency. For the useful effect of the Volunteer is
184 EP, which is an efficiency of only
Rv'
550
=
721 x 14
R v
550
184 x 100
91-5
6010 16
-20 per cent.
1010145.75 EP
And the useful effect of the Viper and Vixen is
which makes the efficiency of the Viper, the best of thetwo,=145
145-75 x 160
6510-22-37
per cent. only, instead of 25 in the table. Moreover,even this small efficiency
was obtained onlyin smooth water under all the favourable circumstances oftrial
which are sought for on such occasions, and which never can be combined
continuously at sea in consequence of the rolling and pitching of the ship and
shocks of the waves. For no movement of the propeller can be made in an
unfavorable manner, or a drop of water be sent in the wrong direction
without entailing proportionate loss, and this must necessarily be great in
tossing and rolling. From these evil effects of my system of propulsion is free,
pitch and roll as the ship may. We will therefore now analyse the components
of such system by giving the
PRACTICAL MODULUS OF EFFICIENCY OF BOYMAN'S SYSTEM OF HYDRO-

page_text: which will be found in my two Specifications of May and December 1866.
Doubtless some errors may be found therein, in the first especially, because
my Provisional Specification was filed only one month after the discovery of
the loss of primary velocity; I was therefore unable in so short a time to see
all the mathematical relations of so new and complicated a matter, which is even
now denied altogether by two distinguished scientific mathematicians,though
the whole subject has been so fully and so often brought before them... We see
therefore how superior is discovery byinduction to any other method,especially
to the mathematical, which never could have made it, since the first
mathematicians cannot realize such discovery even when made. Yet, placing
all reliance on the power of induction, I ventured to begin my Provisional
Specification of the 29th May 1866, one month only after the discovery was
made; with these words, "The object is to save more than one-third of the
"fuel consumed in paddle wheel and screw propulsion, besides the pro-
"portionate cost and weight of engines, boilers, water, and propellers.""
The contempt with which this assertion has been received may be supposed
when the first authorities on the science of propulsion assert that the efficiency
of the best screw and paddle wheel vessels (the Victoria and Albert, for
instance) is 65 per cent of the indicated power. This is 81.25 per cent.
of the power imparted, because there remains only 80 per cent. at disposition,
as 20 per cent. is not imparted at all to the propeller, being consumed in
friction. If then of the remaining (80-65-) 15 per cent. we allow so
little as 10 per cent. for residuary velocity and only 5 per cent. for shock,
&c., there does not remain even one per cent. to be saved, according to the
first writers on the paddle wheel and screw.
"
It has however been shown how my prediction in May 1866 (of" a saving
"of more than one-third of the fuel consumed in paddle, wheel and screw
'propulsion ") has now been verified by the Admiralty official trials of the
Waterwitch, Vixen, and Viper. Therefore the remembrance of my minute
steam jet experiments on action and reaction (1866-1842-) 24 years
after they were made, and their application by induction in 1866 to the
paddle wheel and screw as planes, referred to in my Provisional Specification
of May 1866, p. 7, will revolutionize the steam navigation of England and
the world, save largely in fuel and first cost of engines, give a system of
propulsion reaction, which will never be superseded, lead to aerial navigation,
and become the only standard measure of the resistance of vessels,-"a
"knowledge of which," as Herschel says in his Natural Philosophy, p. 236,
"is of great importance in naval architecture."
..I believe that my system of hydro-propulsion is the only Invention reduced
:

page_text: to an exact science patented since the Patent Laws in 1623, I wish therefore
to point it out to show that this is not a mere mechanical invention in which
the machinery is the first thing and the last, but a philosophical Invention
based on a knowledge of the laws of physics, hydro-dynamics, and hydraulics,
that these are the first things to be understood, not knowing which has rendered
abortive all the efforts of two centuries, from Togood and Hayes Patcit
in 1661 to Her Majesty's Waterwitch in 1867. "Let us first find out a
"thing, and there will be no lack of persons to put it into shape," is a remark
of the philosophic D'Alembert, applicable I think to this kind of Invention
where we cannot put a thing into proper shape without first discovering the
laws which govern its action.
Now the method in which this was done is a good illustration of the
following remarks of the late Master of Trinity College:-"There is the
"same essential element in all inductive discoveries. In all cases facts.
"before detached and lawless are bound together by a new thought. They
are reduced to law by being seen in a new point of view. To catch this
"new point of view is an act of the mind, springing from its previous pre-
"
26
6
paration and habits. The facts in other discoveries are brought together
"according to other relations, or as I have called them ideas; the ideas of
time, of force, of number, of resemblance, of elementary composition, of
polarity, and the like. But in all cases the mind performs the operation by
"an apprehension of, some such relations, by singling out the one true
relation, by combining the apprehension of the true relation with the facts,
by applying to them the conception of such a relation.. Moreover, the
"presence of a conception of the mind, as a special element of the inductive
process, and as a tie by which the particular facts are bound together, is
"further indicated by there being some special new term or phrase intro-
duced in every induction; or at least some term or phrase thenceforth
"steadily applied to the facts, which had not been applied to them before,
"as when Kepler asserted that Mars moved round the sun in an elliptical
orbit, or when Newton asserted that the planets gravitate towards the sun;
"these new terms mark thenew conceptions on which the inductious depend."
Whewell's "Philosophy of Liscovery, p. 254."
46
"
"
. We see therefore that it is by such processes of the intellect thai new dis-
coveries are made by induction, and new scientific terms which denote them
added to the common stock of ideas. I may then be allowed to show here,
especially as I can write no more on these matters, what new terms were
found to be necessary to indicate and explain my discoveries referred to in iny
former Specifications of 1866-1. The Time of Repose of Bodies. 2. Latent

page_text: Heat is Latent Force. 3. The Three Areas in One, the Actual, Dynamic, and
Efficient Area of the Paddle Wheel and Screw. And 4. The Three Powers
in One in Aerial Navigation, the Moving Power, the Elevating Power, and
the Renewing Power, as explained in my Specification of 1866, No. 3262,
p. 47, 48.
Now I have there shown, at p. 71, line 36 to p. 77, line 8, that these and
other discoveries, beginning in July 1842,and ending in the discovery of the law
of frictional resistance in October last, 1867, herein-before referred to, were
the successive links in that long chain of philosophic inquiry into the principles
of propulsion which has now extended over a quarter of century, and are
inseparably connected with my discovery in April 1866 of the superiority of
reaction to impulse for navigating the two oceans of air and water.
DESCRIPTION OF SHEET 2.
This represents the water-tight cases, referred to in the presént Provisional
Specification, applied to the kind of hydro-propellers contained in my Speci-
fication of May 1866, to enable them to be drawn into the ship. Four hydro-
propellers work vertically through the bottom into four propelling tubes with
divergent entrance and exit underneath the vessel, but which tubes are fixed
to the propellers to be drawn into their cases with the propellers. The tubes
have a flange all round them which support them upon the vessel, and prevents
the water getting into the cases or out of them when used as bilge and fire
pumps.
Fig. I. shows a sideelevation of part of the ship and hydro-propellers; Fig. 2
shows a part plan of the engines and propellers; and Fig. 3 shows a vertical
midship section through the engine room. The same parts are marked with
the same letters in all the views.
The forward propellers a','a', are worked by three engines independently of
the after propellers a, a, which are also worked by three engines. The engine
shafts b, b, are driven by the steam cylinders c, c², c¹¹, which are attached by
their connecting rods to the cranks d, d'. The engine shafts pass through the
water stuffing boxes in the water-tight cases in which the propellers and their
tubes are moved. On the ends of these shafts are fixed discs g, which by
means of a slot and pin h drive the discs i fixed on the ends of the propeller
shafts. The propellers when not in use can be drawn into their cases by the
screws and worm gear k, and the opening in the ship's bottom can be closed
by the slide valves / by means of ratchet wheels. To enable the propellers to
be drawn into their cases they must be disconnected. from the engine driving
shaft. For this purpose the engines must be stopped in such a position as

page_text: will bring the slots even vertically upwards for the pin h and its connections
to be drawn up. It will be seen that the disconnecting apparatus here
described is similar to that shown in Sheet I. and herein-before described.
I will now show how these water-tight cases may be turned into leak and
fire pumps, though not referred to in my Provisional Specification, and
therefore not intended to be claimed. There are 2 vertical cut-off valves
m, m', one m¹ before and one m behind each propeller tube for the following
purpose-Each end of the hydro-propellers has two openings, one from the
end of its case into the water-tight case, and one from the end of the propeller
tube into the external water. When, therefore, the cut-off valves m and m
are both raised they cut off the opening from each end of the propeller case,
leaving the propeller tube open at each end for the entrance and exit of the
propelling water. The vertical valve p is the bilge valve for the purpose of
opening and closing a communication between the case and bilge or leak water,
and o is the passage from the case into the fire pipe, the valve of which is
outside the water-tight case.
The side elevation, Fig. 1., shows the cut-off valve m at the back of the
propeller tube raised. This closes the communication between the propeller
case and water-tight case. The cut-off valve m' at the front of the tube is
shown lowered, closing that end of the propeller tube to prevent the entrance
of the propelling water into the tube, opening at the same time a communi-
cation between the propeller case and water-tight case on that side for the
passage of the water, as shown by the arrows. The vertical valve q is for
turning the vessel, and is shown open at the side of the propeller tube for the
water to he ejected at right angles, as shown in Sheet 3. But this opening
must be closed when the case is used either as a bilge, fire, or force pump.
When the case is used for a bilge or leak pump the cut-off valve m¹ must
be screwed down in the position shown, when it will also open a communica-
ion between the case and propeller tube, as before said. The bilge valve p
must be screwed up to open a passage into the case.
owards the stern in the direction of the arrow will then create a partial
acuum in the propeller case and so draw in the bilge water by suction as it
s called, into the case round the top and both sides of the propeller case in
he water-tight case, and so into the propeller tube in direction of the arrows
n the right of the Drawing, Figure 1., and so propel the vessel by the bilge
r leak water by reaction at m, if sufficient for the purpose.
The floats moving
When the case is used as a fire or force pump the valve m must be raised,
hich will cut off all communication between the case and propeller case on
at side, and at the same time open the propelier tube to the external

page_text: water. The valve in the fire-pipe o must be opened, and the cut-off valve
m at the back of the propeller tube must be lowered. This will close the
communication between the external water and propeller tube at that end,
and at the same time open the passage between the propeller case end and
water-tight case. The external water will be drawn in by the propeller floats
through the tube in the usual way at m³, but be unable to get out behind. It
will therefore be forced round the propeller case at the end m, so round to
the fire opening at o, at which passage only it can escape, because all other
communication is closed. It is scarcely necessary to observe that the fire
passage o and bilge valve p can be made at both sides of the case if a greater
delivery be required. Now as the whole engine power can thus be used for
leaks and fire, both for commercial and war purposes, we have for the first
time in steam navigation the greatest possible securityagainst its two greatest
dangers. It is plain that no extra, leak and fire pumps need now be
taken, thus saving their cost, weight, and space, besides the liability to get
choked by their small passages. Such pumps s also are not always in perfect
working order from disuse, which has often led to the destruction of life and
loss of ship and cargo.
The lower cam inside the propeller case in Sheet 2, Figure I., is not to be
used with the upper cam, but is only introduced to show how the principle
may be varied in application. Should the lower cam be preferred the bite or
jam pressure in the slits of the drum due to long leverage in a cam at the end
of the floats may be relieved by a friction roller on each side of the slits in
the drum in which each float slides, and another roller in the middle of the
float at its top.
DESCRIPTION OF FIGURE 3.
Figure I. shows a plan of a ship's bottom and how the ship is turned on its
centre. To do this the forward engines only are reversed, one of the forward
cut-off valves must be lowered, and the turning side valve q in the propeller
tube raised, as shown in Sheet 2, Figure I, and also in Sheet 3. The water
will then enter from the stern, and being unable to get out at the end of the
tube will rush out at the side, as shown in the Drawing, Sheets 2 and 3. The
cut-off valve of one of the stern propellers on the opposite side must also be
lowered at the stern end of the tube, and the side turning valve q be raised.
The water will then be forced out with the whole force of the engines at right
augles from two of the propeller tubes, and horizontally from the other two.
And as the distance of leverage will be considerable the ship will readily obey
such powerful influence, and turn in small compass. This method of

page_text: pecification.
It is said that if the stream of one propeller act upon another there
I have not at all
a loss proportional to the velocity of such stream.
onsidered this question, and have not time to do so here. But if such be
he fact, and the distance between the fore and aft propellers cannot be
ncreased sufficiently to bring the residuary velocity to rest, there is ample
readth of vessel for one pair of hydro-propellers to be set so much further
apart that the stream from one tube cannot enter the one behind it.
CLAIMS.
In my Provisional Specification I have said, "No part of my present. im-
Also that
provement is new of itself, but the combination I believe is."
"a slight difference in form or position makes a great difference in results in
"hydro-dynamical propulsion." Unless, therefore, I define what I do not claim
the principle and application of my combination may be considered to have
been combined before.
in
I do not claim a screw to act as a hydro-propeller or pump when working
in a vertical barrel in the manner shown in Hale's Patent of the 22nd of
December 1827, No. 5594. That is inside the vessel; the discharge or pro-
pelling water is also taken in from the bottom of the boat, both of which are
contrary to my principles and application. Further, the Patentee says
page 1, line 22, that his "Improvements consist in a machine applied to the
"purpose of producing rapid motion of a certain quantity of water, which I
"take in from the bottom and expel with great force from the stern." And at
page 2 he says "I am aware that the rapid expulsion of water from the stern
"or sides of vessels has been before used in several different ways for the
These remarks are extracted to show from the
propelling of vessels."
Patentee's own statement one of the causes of the failure of hydro-propulsion
for two hundred years; namely," the producing of rapid motion and expelling
For this causes so great a loss of power in residuary
0 "it with great force."
velocity as to make all such lawless methods of applying water for propulsion
practically worthless, showing a wrong proportion of parts, that is, too small
an area of reaction, and consequently too great a residuary velocity,evidence
of complete ignorance of the fundamental principles and application of hydro
35 pulsion to make it economically useful.
"
I have shown for instance in my Specification of May 1866, p. 36 and 37
and in my specification of December 1866, p. 13, in what manner the area o
reaction must be found, which formula I have since reduced to its simples

page_text: expression, and herein-before given. For economical hydro-propulsion the
area of reaction should be found by such formula, for a velocity of the entering
water Vabout 1.3 to 1.5 times the velocity of the vessel v. V=2v is not an
economical application in my opinion.
Nor do I claim the same kind of screw as Hale's when working in a
cylindrical barrel or tube inside the vessel in the manner shown in Walker's
Patent of the 18th of November 1843, No. 9733. For the propelling water
though drawn in in the right direction for hydro-propulsion, is drawn in
through a cylindrical opening, instead of a divergent one,as in my Patents of
May and December 1866, and in my present one. The propelling water is
moreover moved through two or more passages before and behind the cylinder
of some length of pipes, and through bends, and expelled for reaction at the
bottom of the vessel, all which are opposed to the principles discovered by
me and their application asenunciated in the Specifications of my said Patents.
Further, I can no more find in this Specification than in Hale's, Ruthven's
(applied to the Nautilus and Waterwitch), or any other known to me, any
evidence of the fundamental principles of the science of hydro-dynamics or
hydraulics for propulsion, nor how to find the proper proportion of area to
resistance in order to overcome it in such manner as to make hydro-propulsion
an economical application of power. I believe, therefore, that I am the first
and only one who has done so, as set forth in my Specification of May 1866,
No. 1497, p. 37, and elsewhere.
Nor do I claim the ordinary screw propeller working in a long or short
cylindrical horizontal tube inside or outside the vessel shown in the Patent of
De Penning of the 31st of May 1854, No. 1205. For though such kind of
propeller works in an external cylinder, it is still governed by the law of fluid
impulse discovered by me in April 1866, as stated in my said Patent of May
1866. It is therefore subject to the loss of primary velocity and power from
the reaction or back rush of the water escaping past the blades of such a
screw. The fundamental principle and application of my present combination
of screw hydrc-propeller and tube is still,as in my two former Patents of May
and December 1866, to prevent such escape of water and consequent loss of
power, as will be seen in my Provisional Specification of May 1866, No. 1497,
p.8, line 24 and 25, and elsewhere, to which I have referred in the Provisional
Specification of this present Patent.
Therefore to prevent such escape of water past the blades of the ordinary
screw propeller I have a two or more threaded screw which fills up the whole
screw hydro-propeller tube, as shown in Sheet I. But not merely is the screw
in De Penning's Patent the ordinary screw propeller, but it works in a

page_text: cylindrical tube, which is also contrary to the laws of hydro-propulsion and my
application of them by a divergent entrance and exit. My screw hydro-
propeller tube therefore has also a divergent entrance and exit to prevent the
loss of vis viva and power due to the formation of the contracted vein in the
entering water, which is the vena contracta of Newton, but discovered by me
independently in 1847. Newton, however, did not discover the loss of vis
viva, and consequent loss of power due to the formation of the vena contracta
in water entering a cylindrical tube. This is one of my discoveries for hydro-
propulsion, which not being known in my trial of 1847 (referred to in my
Specification of May 1866, p. 2) rendered all that expenditure useless. The
important practical law of physics which forms the contracted vein and entails
so great a loss when water enters a cylindrical tube, and the divergent pro-
peller tube to prevent it, will be found in my said Specification, p. 8, line 20
to p. 9, line 2; p. 42, line 19 to p. 13, line 19; and at p. 60, line 7. Such
divergent propeller tube isone of the fundamental principles and applications of
mysystemofhydro-propulsion,andisshownwithand withoutexpandingandcon-
tracting valves in all the Drawings annexed to my two former Specifications.
Having shown what I do not claim, and the practical value of a divergent
entrance, I will now show what I do claim :--
1. The combination of the kind of screw and method of working it herein-
before described with my submerged horizontal propeller tube with divergent
entrance and exit. I also claim such combination with or without my
expanding and contracting valves for reaction propulsion; such kind of screw
hydro-propeller and tube being to prevent the escape of the fluid set in
motion by the propellers, and thus obtain direct reaction for water and aerial
navigation by making the medium of resistance the means of overcoming it,
which combination is shown in Sheet I.
2. I also claim the water-tight cases and machinery connected therewith,
to enable the hydro-propellers and tubes to be moved in and out of the
vessel to be repaired, and to convert it into a sailing vessel, as herein-before
described, and shewn in Sheets 1 and 2. It will be seen, by reference to my
Specification of 1866, No. 3262, Sheet I., that only the steam jet and
equivalent tubes can there be moved in and out of the vessel, and not the
propeller tubes as herein contained; also that the method of moving them is
different.
3. I also claim to make. hollow from the axle to the projection of the
floats such floats as movein and out of a drum for hydro-propulsion; or, which is
the same thing, holes therein to let out the water which gets pent up between the
thickness of the floats and axles as they are moved out of the drum. This

page_text: may seem a small matter, but the success of great things depends on the
efficiency of small. The floats to which I refer are shown in my Specification of
1866, No. 3262, Sheet, Figures 1 and 3, and must not of course be made
to let out any water at the sides of the floats.
I do not confine myself to the mere details of the combinations herein-before
described, because these may be varied, yet still preserve those fundamental
principles and objects and proportionate areas of reaction embodied in the
applications before described, and which are necessary to make hydro-
propulsion an economical application of power. For though I call my system
of hydro-propulsion external divergent to distinguish it from all others I
know of, I have shown a variation of my propeller tube in Sheet I., Fig. S.
This is the same variation of the tube (not of the propeller) as is shown in my
Specification of December 1866, Sheet I., Figure 8. But both are departures
from the less curved normal propeller tube shown in the same Sheet, Figures
2 and 4, also in my Specification of May 1866, Sheet 1, Figures 1 and 4, and
Sheet 2, Figure 5, entailing therefore proportionate loss of power, as every
departure from the normal must do.
In claiming the proportionate areas of reaction embodied in the application
before described necessary to makehydro-propulsion aueconomical application
of
power,
it must be understood that I do not claim such proportionate areas
of reaction for such an application as is contained in the Drawings of the
Patent taken out by me in the name of James Pedder in, 1847, No. 11,946.
Nor for such an application of hydro-propulsion as is contained in Ruthven's
Patent of August 1849, No. 12,739, applied to the Nautilus and Waterwitch.
Nor for such an application as is contained in the Patents of Hale, Walker, or
De Penning before referred to. For although I am the first discoverer, as far
as I know, of the method of finding the proper area of reaction for economical
hydro and aero propulsion contained in the formula R= (-3+ (-6)² a, w
2 Va (V) lbs. and to discover the proof of this formula in the laws of
gravitation enunciated in my Specification of 1866, No. 1497, p. 21 to 24,
and p. 26 and 27. Still I limit my claim to the proper proportionate area for
hydro and aero propulsion to the combination herein-before described of the
screw hydro-propeller and propeller tube. It must also be observed that the
whole value of my system of hydro and aero propulsion depends on my
discovery in April 1866 of the law of fluid impulse and consequent small
efficiency of the paddle wheel and screw as propelling instruments, enunciated
in my Patent of May 1866, No. 1497, p. 7, and elsewhere.
29
In my Specifications of 1860 and May and December 1-66 I have recorded
the state of the science of propulsion at those periods because of the interest as

page_text: well as importance of knowing the principles and practice of every science at
the time of any departure from them, because also we can better tell what
is new. I will follow the same practice here by showing how hopeless
hydro-propulsion is considered by the best authorities, those who have most
considered it.
No one has written so much on this subject as the Reverend 1. A. L. Airey,
A.M., Professor of Mathematics in Merchant Taylors' School; his papers
will be found in the "Engineer" and "Engineering" from October 1866 to
September 1867, and as the Professor was on board the Waterwitch during
her best performance he had every opportunity of examining the principles
and application. In one of his papers in "Engineering" of the 30th of
August 1867, this admirable mathematician observes :--"The only claim I
"have to form or express any opinion on hydraulic propulsion is founded ou
"a careful study of the subject for the last seventeen years, and my sole aim
throughout has been to make science what it ought to be in such cases to
"the practical inventor, the eye to the hand. Professor Airey first became
acquainted with hydro-propulsion by my asking him in 1849 to report on my
discoveries in this science, which he did on the 30th of August 1850; but
how greatly we differ will be seen by the following remarks of his in
Engineering" of the 13th of September 1867-"Even under the most
"favorable conditions attainable hydro-propulsion is worse than the besi
examples of the screw."
"
44
"
In this opinion the Professor is confirmed by every writer on the subject
whose investigations I have seen. The editor of the same journal of the
13th of December 1867, not two months ago, observes, in speaking of "the jet
propeller," it might be said that it would be now premature to " pronounce
upon its future, but it is never premature to apply fixed principles to any
"question of engineering design, and here it appears that the water jet is
"placed at a disadvantage in respect of the weight and friction of the water
"in the large passages which are requisite, and because also of the loss of
"efficiency in any centrifugal or other machinery employed to put the water
"forming the jet into motion." I believe, therefore, that out of the whole
world of some thousand millions of souls I am the only one who believes in
the superiority of reaction to impulse for propulsion in air and water,and that
nydro-propulsion is a more economical application of power than the paddle
wheel and screw. For I have herein-before shown that my system, instead of
being "worse than the best examples of the screw," as affirmed by Professor
Airey, "after a careful study of the subject for the last seventeen years," will

page_text: save 86 per cent. of fuel on the Vixen and Viper twin screws built by the
Chief Constructor of the Navy, and engined and screwed by such first-class
engineers as Messrs. Maudsley and Field.
Having had occasion to refer to my three former Specifications of 1860, and
May and December 1866, it is proper to observe that any errors in the
formulæ therein, or in this Specification, must not necessarily be attributed to
me, nor to any carelessness of the printers, because of the difficulty of getting
mathematical formulæ correctly copied twice by those unaccustomed to them,
and then printed and examined. There is, for instance, an error in one of the
formulæ in my Specification of December 1866 at p. 15, line 7, the only one
I have yet examined, instead of " it should be R(), and RV in line
10 should be omitted. The mathematician will at once see this from the
principle of the formulæ enunciated.
In my Disclaimer also of the 31st of December 1867, No. 1497*; 6 has
been mistaken for at p. 4, line 13, and at p. 8, line 6. The formula should
be (d+b)
2db
This Specification, the third of the like nature,concludes, I hope and believe,
the philosophic studies of a quarter of a century directed chiefly to an enquiry
into the principles of propulsion, beginning with my first discovery of the law
of fluid impulse in July 1842, the foundation of this my two previous Patents,
and ending with my last discovery in October 1867 of the law of the frictional
resistance of vessels, confirming the discovery 25 years before. Believing that
iny system is the ultimate development and reach of science for propulsion
in air and water, that it will therefore supersede all other systems, and
never be itself superseded, I hope I may remark unblamed that I began my
inquiries without knowing the meaning of algebra or decimals, or one
principle of scienceor mechanics, evidencethatnothingisdeniedtoperseverance
in the right path.
In witness whereof, I, the said Richard Boyman Boyman, have hereunto
R. BOYMAN BOYMAN. (L.S.)