1825.] 
by a rack and pinion ; and the mould has a 
wedge-shaped channel extending its. whole 
length. Into this channel the melted metal 
flows from the pot; and the parts of the 
mould are filled as they pass the lip of the 
melting pot, while a stop-plate presses 
against and closes the channel as the mould 
adyances. The core has one or more small 
erooves extending its whole length, for con- 
ducting the steam and air from the mould ; 
and, in order that the steam and air may 
pass iuto the grooves, the surface of the 
core is coated with paper, or other porous 
matter. One of the most important appli- 
cations of this mode of casting is, to mak- 
ing leaden PIRES; and in forming these 
pipes, the mould descends vertically as it 
fills with melted metal. The castings may 
obviously be made of considerable length, 
as fifteen, twenty, thirty, or more feet. 
The fluid metal may be of a low tempera- 
ture, and, consequently, free from bubbles ; 
and the regular union of its parts will not 
be interrupted by its having to move in the 
mould. it may, further, be remarked that, 
with the exception of the last part, which 
is formed, of each length, the metal will 
consolidate under a considerable pressure 
of semi-fluid metal, a circumstance which 
is well known to produce compactness and 
strength. 
The patentee intends to apply his pro- 
cess to casting sheets of lead, and various 
other articles, required in such. lengths as 
to render the application of this improyve- 
ment desirable. It will scarcely be neces- 
sary to point out, to our readers, the advan- 
tage of being able to cast lead pipes, ina 
sound and perfect manner, in long lengths ; 
but it may not be so obvious that pipes 
east well are much better than drawn pipe. 
By drawing a pipe the longitudinal cohe- 
sion is increased ; but the lateral cohesion, 
or strength to resist splitting, is diminished ; 
and as the strain on a pipe always tends to 
split it, it must be evident that drawing 
tends to weaken a pipe, in that direction in 
which it is most essential that it should be 
strong. 
‘o Jostan Parkes, of Manchester, Lanca- 
sea for a Method of manufacturing Salt. 
4th Dec. 1823. 
Tue object of this invention is, to afford 
the means of removing the concentrated 
salt from the evaporating pans or boilers, 
without stopping the process of evaporation. 
To effect this object, the boiler is a close 
hoiler, and made of the form of the frustum 
of an inverted cone, terminating in a small 
cylinder at the bottom, and enclosed by a 
dome, or hemispherical top. The fire-place 
is fixed above the level of the small cylinder 
which forms the lower part of the boiler, 
and the flame and smoke circulate round 
the conical part of the boiler. The brine 
is admitted into the boiler, at two. places, by 
pipes; the one is near the bottom of the 
cylinder, and the other is, nearly, at the 
New and Expiring Patents. 
349 
height to which the boiler is. to be filled 
with brine, during the process: ~ each of 
these pipes. is furnished with a stop-cock. 
The yapour rises in the dome, and passes 
off through pipes at the top. The concen- 
trated salt is let out by a cock in the bottom 
of the cylinder, which terminates the lower 
portion of the boiler. 
One hour is mentioned as the time, in 
which a sufficient concentration of the salt 
will usually take place, in a boiler kept full 
of brine; but, of course, depending on the 
heat applied, and the size of the boiler: 
and, during this time, the lower pipe, for 
supplying brine, is kept shut, and the upper 
one just so far open as to supply the loss 
by evaporation. When the concentrated 
salt is to be taken out, the stop-cock in the 
lower pipe, for supplying brine, must be 
previcusly opened for a short. time; which 
allows a current of cold brine to flow into 
the lower part of the boiler, by which the 
whole of its contents are disturbed, and the 
concentration further promoted. The lower 
pipe is then closed, and a short time being 
allowed for the salt to settle into the cylin- 
drical part of the boiler, it is then let out 
by the cock at the bottom, and coliected in 
a basket or strainer; and the cock being 
closed again, as soon as the deposit of salt 
is obtained, the process of evaporation 
goes on for another hour, and the salt is to 
be withdrawn at the end of that time, in the 
same manner; and so on successively. 
The conditions necessary to the success 
of the operation are, jirst, That the cylin- 
drical part of the boiler, in which the salt 
deposits, must be below the level of the 
fire, and therefore cooler than the other 
parts of the boiler; secondly, That the sides 
of the boiler, against which the fire acts, 
must have a considerable inclination to- 
wards the part which is to receive the 
deposit of salt. The arrangement we have 
described fulfils these conditions admirably ; 
but the patent is for the principle, and not 
for the peculiar arrangement described in 
the specification. 
ee 
A List of Parents that will Expire in the 
present Month. 
For machinery for dragging, locking and 
scoiting the wheels of carriages: to GrorcE 
ALExANDER THomrson, gent. of Parliament- 
street. (Dated May 1, 1811.) 
For a method of applying mechanical 
powers to the propelling of ships and vessels of 
every descriplion through waler : to SrenMaN 
Anams, of Connecticut, America. (Dated 
May 1.) 
For certain improvements in the manufac- 
ture of rudder-bands and bolts for shipping : 
to Joun Dozson, of Newcastle-upon-Tyne. 
(Dated May 1.) 
For a machine for the manufacture of gold 
and silver twist, sill, cotlon or thread twisted 
lace-net, similar to the Buckinghamshire 
lace, as made by hand with bobbins on pil- 
lows; 
