1924.) [14339 
PATENTS FOR MECHANICAL AND CHEMICAL 
INVENTIONS. 
{In an introduction to this department of our work in the October number, p. 241 and 
"in p. 244, we took occasion to mention several particulars regarding the nature and 
operation of Patents for Inventions, with which the public had seemed but imperfectly 
acquainted ; especially as to a supposed sanction, or guarantee of utility, ingenuity or 
novelty, or of legal property, which the mere fact of having obtained a patent is sup- 
posed to confer; it not being generally known, that in every patent are these words, 
viz. “ It is entirely at the hazard of the patentee, whether his said invention is new, or 
will have the desired success.” The Crown, therefore, guarantees nothing; it merely 
grants a prayed-for monopoly for fourteen years, on condition of enrolling a complete 
specification; which then lays the patent open to be infringed, and even repealed 
altogether, at the suit of any one who can prove any thing claimed in the specification, 
or that is described therein, and not expressly disclaimed; which is old, or already has 
been used ; as also, in case of it appearing from the verdict of a jury, that the thing is 
useless, or that the specification is not sufficiently clear and explicit to enable the public 
to understand and use the invention, immediately on the expiration of the patent, in all 
respects as ‘beneficially as the patentee may have. done. . Towards enabling the public 
to avail itself of this important right, we shall publish henceforward the dates and titles, 
and often other particulars concerning the patents expiring in the month which our publi- 
cation bears: also, before the usual period of enrolling the specifications, we intend 
giving a complete monthly list of New Patents granted; and as to the Patents which, 
for their apparent wiilities, we select, to lay an abridgement, or the substance of their 
specifications, before our readers. ] s 
a 
To Joun Vattance; of Brighton, in 
Sussex, for an improved Method of 
Freezing Water, or producing Ice in 
large Quantities.—1st January 1824. 
HE principle of this invention con- 
sists in,passing a current: of arti- 
ficially dried and rarefied air, over an 
extended surface of water, which, by 
impinging upon it, carries off the aque- 
ous vapours, and with them the heat of 
fluidity from the water. The artificial 
drying of the air is proposed to be ef- 
fected by passing it through a leaden 
vessel nearly filled with bullets of the 
same metal; on to which bullets con- 
centrated sulphuric acid is made occa- 
sionally to drop, in order to keep their 
surfaces wet, and so expose a very 
large surface of the acid to the passing 
air, admitted by the same very small 
and adjustable aperture in the bottom 
of the vessel by which the waste acid 
escapes, in order to extract from the air 
its aqueous vapour. 
The current of this dried air is in- 
tended to be produced, through pipes, 
to and from the freezing vessel, by 
means of two powerful air-pumps work- 
ed under water, with alternate strokes, 
and used to reduce the pressure in the 
vessel to about half an inch of mercury, 
and so draw off continually this air and 
discharge it, after it has performed its 
office of impinging on the surface of the 
water, kept at about half an inch deep, 
and has saturated itself with moisture 
therefrom. 
' Moyrury Mac. No. 403. 
The first half-inch of water is intended 
to rest on the broad flat bottom of a 
cylindrical vessel, of sufficient capacity ; 
and when this water is become ice, a 
second half-inch is to be introduced 
upon this ice, and this frozen in its 
turn: then more water to the like 
thickness is to be admitted, and so on, 
until the vessel is as nearly filled with 
solid ice as the apparatus next to be 
described will admit. 
In order to cause the dry air to im- 
pinge on the centre of the surface of 
the water, and to sweep over every part 
of it, towards the circumference, a 
loosely-fitted piston plate, rather hollow. 
upwards m the middle, and having a 
long hollow piston-rod, is suspended 
almost at the smallest distance possible 
above the water’s surface. _ It is down 
through this hollow rod that. the dry 
air is admitted, and passes up round the 
edges of the plate to the suction-pipe 
of the air-pump, which enters the freez~ 
ing vessel just under its close-fitting and 
yet moveable lid. In the centre of this 
lid is a stuffing-box, through which the 
hollow piston-rod slides upwards the 
space of half an inch, previous to ad- 
mitting each fresh quantity of water. 
The upper end of the piston-rod slides 
through another stuffing-box into, the 
pipe (or connecting vessel) coming from. 
the vallast vessel. When the piston. 
plate has arrived almost at the top of 
the freezing vessel, the pumps cease 
working and the lid is unfastened, and, 
3K with 
