gems himself-with'h a 
_ shapé of'a pantaloon; that covers him all but his eyes, 
~~ ‘and is made as wet as 
. GLASS. 
: must be taken out with iron hooks and forks, and a 
ily put in its place through the 
For this work, the man 
~  hertege 
‘made of skins, in the 
by the herds ‘ily 
le. ‘Theeyes should be de- 
fended with a very thick plate of glass. 
Secr. II. On Bottle Glass. 
The bottle-house furnace, represented in Plate 
CCLXXV. Fig. 1, (see description of Plates, ) is gene~ 
rally see bid Sn chamber, arched over with the 
same material. Some give it a very flat crown, as itis eall- 
_.ed; and others raise it high and ofa barr shape. This 
furnace is erected in the centre of the building, on the top 
‘of the cave or vault, and is divided into three spaces in 
the inside by the grate, and on each side of that is the 
site for the pots or cfucibles, which is a bank of the 
same material as the furnace, generally about a foot 
ligh, and three broad. 
n this furnace there is a hole about a foot diameter 
for each pot, called working holes, at which the. work- 
men put in the materials, and take out the liquid glass. 
P< ‘At each angle of the furnace there is also a hole about 
e same size, which communicates with the calcining 
arhace ; and the flame that issues from the main fur- 
nace, which otherwise would be lost, reverberates on 
the materials in this furnace, and calcines them. There 
are generally eight other furnaces or arches in a bottle- 
house. Six are used for annealing the bottles after they 
are made, and two for annealing the pots, previous to 
ing them into the main furnace. 
The materials used for bottle glass are of the coarsest 
kinds. Government will not allowany but the commonest 
sea or river sand, mixed with soap boiler’s waste, which 
is done in the proportion of three of soap waste to one of 
sand, according to the quality of the soap-waste : this 
Soap-waste is generally calcined in two of the arches 
used for that purpose, and termed the coarse arches, 
which are kept at a red heat from 24 to 30 hours, the. 
time required to melt the materials and work them into 
glass, which is called a journey ; after that ‘the soap- 
“waste, now termed ashes, are taken out and bruised 
and mixed with the sand in the proportions already 
mentioned. The mixture is then put into the fine 
arch, where it is again calcined during the working 
journey, which is generally 10 or 12 hours more. When 
the working journey is over, the pots are again filled 
with the‘red hot materials out of the fine calcining arch, 
In about six hours it is melted; the pots are again fill- 
_ ed up, and this second filling requires about four hours 
- to melt. 
By continuing the heat to as great a d as possi- 
ble, in the course of 12, 15, or 18 hours, these materials 
become a perfect fit for making wine bottles. The 
furnace is then reduced to a working heat, by shutting 
the cave doors, and excluding the air from the grating. 
‘The metal, as it cools in the pots, becomes more dense; 
and all the ous matter that was contained in 
the ashes, and not melted into glass, floats on the top 
and is skimmed off. The furnace is then filled witn 
coal, in such a way that it will retain what is termed a 
working heat, for four or five hours, when it is again 
filled so as to preserve that degree of heat till the working 
a, is finished. _It is impossible to give any correct 
the process of blowing to a that never 
Saw glass manufactured. There are six people employ- 
ed in the making of one bottle, independent of ali the 
men employed in preparing the materials, each per- 
forming a distinct part ; and by that division of labour, 
they are enabled to make a very large quantity in: a 
journey ; and ea ten men and boys are busily 
working: with long hot irons, and red hot gisss metal 
in a liquid state, in a space not exceeding four square 
yards, yet such is their regularity im passing one ano- 
ther, and handing back and forward their work, which 
never fails to strike a stranger with terror, that it is very 
rarely any of them meet with an accident. 
One workman, called a gatherer, dips the end of a tube, 
heated red hot, and about five feet long, into the pot 
containing the metal, to which it readily adheres ; and 
after it is cooled a'little, he again immerses the end of 
the tube so as to cover the metal ; and, by giving it a 
turn im his hand, he is enabled to bring out of the pot 
as much as is required for a common wine bottle. He 
then hands it to the blower, and pre another ; 
while the blower, by rolling the metal on a stone or 
piste; brings it to the end of the pipe or tube: he then 
lds it in a brass or cast-iron mould, and, by blowing 
down through the tube, makes the glass, which is now 
getting cold, retain the shape given to it, which is that 
of a common wine bottle. It is then handed to the finish- 
er, who, by*means of a cold piece of iron with which 
he touches the neck while still red hot, but cold enough 
toretain its shape, cuts it off from the blow-pipe, as 
completely as if done by a diamond. 
Secr. III. Broad or Inferior, Window Glass. 
This species of glass consists of different ingredients, 
and is manufactured in a different manner from crown 
window glass. Its ingredients are, soap boiler’s waste 
6 bushels ; kelp 3,.do, ; sand 4 do. 
When these materials have been calcined for from 
20 to 30 hours, they are removed with iron shovels, 
while red hot, to the melting furnance, when the pots 
are filled with it. By exposure to the heat from 12 or 
15 hours, the whole is reduced to a fluid state. . It is 
then taken out upon tubes in the manner described 
under Sect, IV. and blown into globes of nearly a foot 
in diameter, These globes being carried to the mouth 
of the oven, a longitudinal and nearly rectilineal crack 
is produced,-by touching it with a cold iron dipped in 
water. The globe is then opened on a smooth iron 
plate at the mouth of the furnace, and then forms a 
circular sheet of thin transparent window glass, See 
Parke’s Essays. 
Sect. IV. Crown Glass. 
The furnace for crown glass, represented in Plate 
CCLXXYV. Fig. 2. (see description of Plates, ) is general- 
ly constructed for four or six pots of such a size as will 
contain from 16 to 20 cwts. of glass. There are also seve- 
ral other furnaces required in this manufacture: A re- 
verberatory furnace for calcining the materials ; flashing 
furnace, and bottoming hole, used for the purpose of 
heating the glass, in order to continue its flexibility 
till it acquires from the workman the desired shape, 
with several others called arches, which are used for 
the purpose of annealing the glass after it is made, 
and the A sg previous to their being set into the fur- 
nace. The materials for crown glass, that is the best 
window glass, are two parts of kelp to one of fine white 
sand; these are the usual proportions ; but the qua- 
lity of even the best kelp is extremely various, some 
vitrifying more and some less sand. From six to eight 
ewt. of these materials, after they are well mixed, 
are put into a reverberatory furnace, of about six feet 
309 
Crown 
Glass. 
sa) 
Method of 
making 
bottles, 
Broad glass. 
Crown 
glass. 
PLATE 
CCLXXV. 
Fig. 2. 
