Cr $2.53 [Aug. 1, 
MECHANICAL AND CHEMICAL’ 
INVENTIONS. ; 
—< > 
[Zn pursuance of the design announced by the Compiler of this department of our Work, in 
vol, lviii, p. 241, and further explained in pages 244, 433, 533, &c., of making this as 
useful to our ingenious, mechanical and manufacturing readers, as the space we cun pos- 
sibly allot to it will permit,—we have to notice here, the commencement, on the 1st of July, 
ofa New Title and Series (the Third) of the: Monthly Work, chiefly.on Patents, anony- 
mously commenced in 1794, and ever since so continued. Instead of ‘‘ The Repertory of 
Arts,” the same is now denominated “ The Repertory of Patent Inventions ;’? which, 
besides inserting, as heretofore, verbatim (and with copies of all the drawings, in most cases), 
the Specifications of a limited number of the Patents, this Number has commenced the 
plan (heretofore almost exclusively followed by Mr. W. Newton, in his “ London Journal of 
Arts””) of giving abstracts of recently-enrolled Specifications, and of their accompanying 
drawings :~ and also (which principally occasions our present notice), “A Compendium of 
the Law of Patents,” in Parts, separately paged, so as to admit of separate binding.— 
Reverting to the Abstracts, or “ Abridged Form of Specification,” promised in this New 
Series, justice requires us to condemn the beginning made, by devoling seven and a half pages 
to discussion on, and to the representing as, ** an extremely ingenious invention, the best for 
the purpose yet made public,” (p. 59), what appears to the writer hereof, the very wildest 
and most impracticable of loco-motive schemes—an associate, as this abstract informs us, 
PATENTS FOR 
of the noted Gas-vacuum Engine. | 
To Francis Drverrux, of Cheapside, 
London, for certain Improvements on the 
French Military Mill, used for grinding 
Wheat and other Articles.— 8th January 
1824. 
HE principle of invention, here, con- 
sists in attaching the moveable steel 
plate, answering to the upper mill-stone, 
in a perfectly firm manner, to the axis on 
which it revolves; and yet so as to admit 
of the grinding-plates being set, to move 
nearer or further from each other, according 
to the fineness or the coarseness of the 
meal intended to be produced. 
This the patentee effects, by affixing the 
vertically revolving plate to its horizontal 
axis or spindle, by means of a screw-box or 
nut, working in a fine screw, cut on the 
axis. ‘This screw-box being preyented from 
turning, and altering the set distance of the 
plates, by means of a ratchet-wheel and 
its click or pall; which Jatter is lifted out 
of the teeth, whilst the distance of the 
plates is being adjusted. All the essential 
parts of one of these mills are enclosed in 
a strong rectangular iron box, to one of 
whose sides the fixed plate (answering to 
the bed-stone) is firmly attached, by screws, 
which also serve nicely to adjust this plate, 
at right-angles to the axis carrying the 
moveable plate; which axis works in crosses 
in the two opposite sides of the box, passes 
through a hole in the centre of the fixed 
plate, and extends sufficiently far through 
the sides of the ox, for fixing on winch- 
handles, or otherwise applying the power 
which is to actuate the mill. The steel 
plates are cut with grooves, in the manner 
ef mill-stones,- and afterwards bardened. 
The corn to be ground descends gradually, 
from a hopper fixed over the space between 
the grinding-plate and the side of the box, 
and passes through a hole cut for this pur- 
pose through the plate above the axis, and 
SO’ gets between the plates and is ground; 
and the meal, being collected by a hopper 
within the box, falls out at the bottom’ 
thereof into a bag or sack, ready to pass to 
the bolting-mill, or meal-sieves. 
To Tuomas Marsx, of Charlotte-street, 
Marylebone, Middlesex, for an Improve- 
ment in the Art of making Saddles.—20th’ 
May, 1824. 
The principle of this improvement con- 
sists in giving greater elasticity to the seat’ 
of a riding saddle, by means of stretched: 
spiral springs, concealed within its stuffing. 
Small wire-worm springs are to be ex-’ 
tended from the front to the’ back of the 
saddle, upon the ordinary packing, by sew- 
ing their ends to the web, or other cover- 
ing of the saddle-tree. A coating of cloth 
is to be put over the springs, left slack in 
the direction of their length, and, in that 
state, to be stitched through to the pack- 
ing, in lines, so as to preserve each spring 
in its proper place, parallel to another; 
the usual covering of leather may be now: 
applied, and the saddle finished in the or- 
dinary way. 
To Jacos. PERKINS, of Fleet-street, London, 
for an improved Method of throwing Shells 
and other Projectiles. —12th May, 1824. 
The principle of this invention is the’ 
enclosing, in a strong chamber of metal, 
which will bear ahigh temperature without 
melting, a quantity of water, perfectly filling’ 
the chamber, aa:d secured therein by a plug of 
metal of greater fusibility ; so that, on heat~ 
ing the chamber in a properly constructed 
furnace, the plug may melt or give way, 
and allow the highly-heated water to flash » 
suddenly into steam, and, by its action on 
the atmosphere, to propel with great force 
the metallic chamber, and whatever else 
may be attached to it as a missile. 
The particular case which the patentee 
has described, as an application of his prin- 
ciples above stated, is that of a rocket, ora 
cylinder of wrought iron, solid and-pointed 
at 
