J50 New Patents ancl Mechanical inventions . [Sept. ], 
way of constructing steam-engines: 
the pistons, &c. of the working cylin¬ 
ders will be formed so as to lessen the 
friction, and by the means of a fluid, 
prevent the possibility of steam passing 
between them aud tile cylinders; the 
valves will be rotary, and so constructed 
also, as by the intervention of a fluid, to 
obviate the possibility of steam passing 
through them during the time it should 
be cut off from the cylinder, and the 
whole will take up less room than 
steam-engines of the common construc¬ 
tion. 
The power obtained by compressing 
elastic fluids in a certain temperature, 
and afterwards allowing them to act in 
a higher temperature, may be made ob¬ 
vious, thus; suppose the elastic fluid 
to be atmospheric air, and that a tube 
contains twelve cubic inches, with its 
natural temperature and elasticity, it 
will require a certain force to compress 
this air into two cubic inches (say a 
weight of thirteen pounds falling one 
foot) ; but, leaving out the considera¬ 
tion of friction, the elasticity of the air 
itself (compressed into this compass) 
would in the same temperature raise 
the same weight to the height whence 
it fell. 44 If then,*’ says the patentee, 
44 I place the tube and air in a tempera¬ 
ture which would double the elasticity 
which the air had in its natural tem¬ 
perature, and then let it expand till it 
had the same elastic force it had before, 
I compressed it in its natural state, it 
will give me back a force which would 
raise 261bs. a foot high, and leave a dis¬ 
posable force of 13lbs. through the 
same height ; aud the same may be said 
of any other elastic fluid.'” 
To Henry Creighton, of Glasgow , 
Civil Engineer ; for a new Method of 
regulating the Admission of Steam 
into Pipes or other Vessels , and for 
the Heating of Buildings and other 
Places. 
This invention consists in the appli¬ 
cation of the force or power obtained 
by the expansion and contraction of the 
pipes conveying and containing steam, 
or by the expansion and contraction of 
other pipes or vessels, bars or rods, con¬ 
nected with, or placed near to the pipes 
for conveying or containing steam, to 
effect and regulate the admission of 
steam into the pipes aforesaid ; and the 
patentee applies this expanding and 
contracting force or power to regulators, 
for admitting the steam indifferent me¬ 
thods, as circumstances may require. 
Such regulators may consist of cocks or 
valves, or other machinery now com¬ 
monly employed. 
He describes different methods by 
which tile aforesaid force or power, ob¬ 
tained by the expansion and contraction 
of the pipes containing aud conveying 
steam, or by the expansion and contrac¬ 
tion of other pipes or vessels, bars or 
rods, connected with, or placed near to, 
the pipes for containing or conveying 
steam, may be applied to the effecting 
and regulating the admission of steam. 
But his invention consists in the appli¬ 
cation of these forces or powers to effect 
and regulate such admission. The 
methods by which the force and power 
aforesaid can be applied to the purpose 
above specified are various. 
To William Davis, of Bourne , near 
Minchinhampton , Engineer ; for cer¬ 
tain Improvements in Machinery for 
shearing or cropping Woollen , or oilier 
Cloths requiring such process. 
Mr. D. claims as his invention, First , 
the application of rotative cutters, made 
of one solid piece of metal, not screwed 
or wedged to a cylinder bar, as has 
hitherto been the practical way of mak¬ 
ing rotative cutters for shearing cloths. 
Second , the application of rotative cut¬ 
ters, in an angular direction. The dif¬ 
ference between this and the application 
of rotative cutters hitherto in practice, 
will be easily understood, as the old 
practice is to place the under cutter, 
known by the name of ledger-blade, 
nearly parallel to the length of the cloth 
to be shorn, or else nearly at right 
angles to the length of the cloth. Third , 
the application of beds, made elastic 
by spiral springs, i>laced nearly at 
right angles to the plane of the ledger 
cutters. 
By the above described machinery, 
one or two kerseymeres may be cut at 
one time, by fixing a thin piece of metal 
between the cutters and middle list, to 
prevent its being shorn; if it is desir¬ 
able to cut one narrow cloth, one half 
of the cutters, or as many as necessary 
may be made to rest by casting of the 
lines. 
His machine will stand in a room 
three feet by seven feet six inches, and 
will cut an end of cloth, of twenty-one 
yards in fifteen minutes, equally hard 
to cloth cut with any other machine, 
free from streaks from list to list, and 
equal from end to end. It does not 
leave those long hairs which rise above 
the surface, as in cloths cut with the for¬ 
mer 
