1824.] 
To Francis Gypson Spitspury, of 
Walsall, Staffordshire, for Improve- 
ments in Tanning, 22d April 1823. 
The patentee in this case, Mr. Spils- 
bury, had been fortunate enough to 
discover and apply a new and very 
efficient principle to the tanning process, 
and might, if he had been well advised 
and assisted in the preparing of his spe- 
cification, have thereby secured to him- 
self all the simple and practicable modes 
ef applying his principle in practice: 
his principle is this, wz. the forcing of 
liquid tanning-matter into the pores of 
hides and skins, and causing thereby the 
expulsion of the spent liquor from the 
pores, and so supplying them with fresh 
tan, until the tanning is completed. 
The specification before us, instead 
of the comprehensive details which are 
hinted at above, is confined to one mode 
only of applying this very fertile prin- 
ciple, as follows, viz. a pair of skins of 
the same size are selected, from amongst 
- those which have been limedand prepared 
in the usual way, and one of them is to 
be stretched flat out on a table, in order 
to take the shape and dimensions of a 
frame of metal, about one-fourth or 
half an inch thick, and one or two 
inches wide, which shall coincide with 
and cover all the outside borders of the 
spread skin, when laid upon it ; another 
exactly similar frame is likewise pro- 
vided, and also a third one of the same 
superficial dimensions, but much thicker, 
so that this thick frame may admit of a 
supply pipe passing through its breadth 
in one end or side of this frame, and a 
discharge pipe also passes through it 
at the opposite end, both of these 
pipes having stop-cocks upon them; a 
third pipe and stop-cock is also pro- 
vided for the exit of air, in the same end 
or side of the thick frame with the sup- 
ply pipe ; besides which, a considerable 
number of small screw-bolts are pre- 
pared, and holes for them provided, to 
correspond,,on the outward edges of 
each of the three skin-frames. 
These frames being in readiness, the 
two selected skins are stretched in the 
proper position, one on each side of the 
thick frame, and then without side of 
the skins the outer frames are applied: 
the screw-bolts are entered in their 
places, and screwed tight up; by which 
arrangements, the pair of skins are 
made to form the sides of a flat air-tight 
bag, into which tanning liquor can bé 
admitted by the supply pipe, and again 
withdrawn by the discharge pipe. 
Patents for Mechanical-and Chemical Inventions. 
243 
A cistern or-tank of tan liquor is pro- 
vided, several feet elevated above the 
ground, from whence there descends a 
pipe, which can be attached at pleasure 
to the supply-pipe of the skin frame 
above described, suspended in a vertical 
position ; then, on opening the two up- 
per stop-cocks, the tan liquor will flow 
down into the space between the two 
skins, and drive out the contained air 
by its exit pipe, and at length the liquor 
will begin to follow, which no sooner hap- 
pens than this latter cock is closed, 
and the supply of tan liquor continues, 
until the skins become and remain 
distended, by the whole hydrostatical 
pressure of the column ‘of fluid de- 
scending from the elevated cistern ; and 
the consequence is, that the tan liquor 
slowly oozes through the skin, and is 
carried off from its surface by evapora- 
tion, or else drops down into a waste 
receiver, thereby making way in the 
pores for fresh portions of tan liquor, 
until the skins become, in much less 
time than by any previous process, 
thorougbly saturated with tan, and con- 
verted into leather of the very best 
quality. ; 
When ‘the tanning is found to be 
completed, the stop-cock of the supply- 
pipe is shut, and the tan liquor being 
then let out of the space between the 
skins, the screw bolts are slackened and 
taken out, and the skins are again de- 
tached from the frames; the outer 
edges, which have been nipped between 
the frames, are next clipped off, and 
then the skins are to be dried and pre- 
‘pared for market in the usual way. 
For each of the different sizes of skins, 
there must be a set, or several such, of 
skin-frames provided, which may be 
made of iron, if the same be kept well 
painted, to prevent staining the skins 
by their rust. 
Through the remissness of this pa- 
tentee, in not having extended his de- 
scriptions and: claims to other modes of 
applying ‘his principle, than as above, 
already has another patentee availed 
himself of some of them, as we: shall 
now proceed to mention. 
To Howarp Frercurr, of Walsall, in 
Staffordshire, for Improvements in 
Tanning Hides and Skins, 19th Janu- 
ary 1824. 
The invention in this case consists in 
the employment of air and water-tight 
vessels or tanks, within which the skins 
are to be exposed to the compressive 
212 force 
