A NEW METHOD OF GENERATING STEAM
Year: 1805

page_text: TO ALL TO WHOM THESE PRESENTS SHALL COME, I, JOHN COX
STEVENS, of New York, in North America, but now residing in New Bond
Street, in the County of Middlesex, Gentleman, send greeting.
WHEREAS His most Excellent Majesty King George the Third, by His
Letters Patent, bearing date at Westininster, the Thirty-first day of May, in
the forty-fifth year of Ilis reign, did give and grant unto me, the said John
Cox Stevens, my executors, administrators, and assigns, His special licence,
full power, sole privilege and authority, that I, the said John Cox Stevens, my
executors, administrators, and assigns, duing the term of years therein
expressed. should and lawfully might make, use, exercise, and vend, within
England, Wales, and the Town of Berwick-upon-Tweed, the Invention com-
municated to me by my Father, of "A NEW METHOD OF GENERATING STEAM,"
in which Letters Patent there is contained a proviso obliging me, the said
John Cox Stevens, under my hand and seal, to cause a particular description
of the nature of the said Invention, and in what manner the same is to be
performed, to be inrolled in His Majesty's High Court of Chancery within
one calendar month next and immediately after the date of the said in part
recited Letters Patent, as in and by the same, relation being thereunto had,
may more fully and at large appear
NOW KNOW YE, that in compliance with the said proviso in the said
Letters Patent contained, I, the said John Cox Stevens, do hereby declare
that the Invention is fully described and ascertained in manner following, that
Is to say:

page_text: From a series of experiments made in France, in One thousand seven
hundred and ninety, by Mr. Belamour, under the auspices of the Royal
Academy of Sciences, it has been found that within a certain range the
elasticity of steam is nearly doubled by every addition of temperature equal
These experiments were
to thirty degrees of Fahrenheit's thermometer
cared no higher than two hundred and eighty degrees, at which tempera-
ture the elasticity of steam was found equal to about four times the
pressure of the atmosphere. By experiments which have lately been made
by myself, the elasticity of steam at the temperature of boiling oil, which has
been estimated at about six hundied degrees, was found equal to upwards of
forty times the pressure of the atmosphere. To the discovery of this principle
or law which obtains when water assumes a state of vapour I certainly can
lay no claim, but the application of it upon certain principles to the improve-
ment of the steam engine I do claim exclusive right
It is obvious that to derive advantage from an application of this prin-
ciple it is absolutely necessary that the vessel or vessels for generating steam
should have strength sufficient to withstand the great pressure from an in-
crease of elasticity in the steam, but this pressure is increased or diminished
The punciple, then,
in proportion to the capacity of the containing vessel
of this Invention, consists in forming a boiler by means of a system or com-
bination of a number of small vessels, instead of using, as in the usual mode,
one large one, the relative strength of the materials of which these vessels are
composed increasing in proportion to the diminution of capacity. It will
readily occur that there are an infinite variety of possible modes of effecting
such combinations, but, from the nature of the case, there are certain limits
beyond which it becomes impracticable to carry on improvements. In the
boiler I am about to describe I apprehend that the improvement is carried to
the utmost extent of which the principle is capable Suppose a plate of brass
of one foot square, in which a number of holes are perforated, into each of
which holes are fixed one end of a copper tube of about an inch diameter and
two feet long, and the other ends of these tubes inserted in like manner into a
similar piece of brass; the tube, to insure their tightness, to be cast in the plates,
these plates are to be inclosed at each end of the pipes by a strong cap of cast
iron or brass, so as to leave a space of an inch or two between the plates or
ends of the pipes and the cast iron cap at each end; the caps at each end are
to be fastened by screw bolts passing through them into the plates, the
necessary supply of water is to injected by means of a forcing pump into the
cap at one end, and through a tube inserted into the cap at the other end the
steam is to be conveyed to the cylinder of steam engine, the whole is then to

page_text: be incircled in brickwork or masonry in the usual manner, placed either
horizontally or perpendicularly, at option.
I conceive that the boiler above described embraces the most eligible mode
of applying the principle before mentioned, and that it is unnecessary to give
descriptions of the variations in form and construction that may be adopted,
especially as these forms may be diversified in many different modes.
In witness whereof, I, the said John Cox Stevens, have hereunto set
my hand and seal, this Twenty-seventh day of June, in the year of
our Loid One thousand eight hundred and five.
Inrolled the same Twenty-seventh day of June, in the year above
written.