DISHES, DISHES EVERYWHERE!
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"Clay," began Mr. Marwood as they went along, "can be shaped in any
one of several ways, you know: either by throwing; by turning; by
pressing it into hollow moulds; by shaping it by hand over another
type of mould; by pressing it into flat ware such as platters and
plates; by making it by machinery over moulds as is done by hand; by
casting it into the desired form; and by compressing it."
Theo looked puzzled.
"The list sounds like a long one," Mr. Marwood went on smiling into
the boy's troubled eyes, "but when you understand the processes you
will find that it is all much simpler than it seems. Before we begin
to investigate any of these methods, however, I want to say just a
word about the moulds over which, or inside of which, the ware is
sometimes shaped; for moulds are a very important feature both of
pottery and porcelain-making."
"What are the moulds made of?" was Theo's first question.
"I am glad you asked, for that is the vital matter," Mr. Marwood
replied. "Many materials have been tried with varying degrees of
success--plaster-of-Paris, alabaster, steel, gun-metal, and brass. Of
course what is necessary is a strong, firm, absorbent material. Clay
moulds break too easily, and also become saturated with water and lose
their shape; metal moulds, on the other hand, while most useful in
making wares decorated with fine, raised designs such as the Wedgwood
figures, fail to seep up the superfluous water. Therefore
plaster-of-Paris has proved the best medium for the purpose. Not only
does it retain its form, but it also takes up a certain proportion of
the moisture from the clay that is moulded inside or outside it."
"I understand," Theo nodded.
The elevator stopped and they stepped out into a vast, well-lighted
room, gray with clay-dust and thronging with powdery workers. At
benches, before revolving wheels, and beside turning-lathes toiled
busy workmen with white, clay-coated hands.
"We will start our program with the potter's wheel, the oldest of
pottery modeling devices," said Mr. Marwood. "It is a very simple
contrivance, you see--just a round piece of board set horizontally on
top of a revolving spindle. As the disc turns the potter shapes the
clay with his fingers, building it up to the desired height and
moulding it to conform to the profile, or pattern, he keeps beside
him. This profile is of wood or steel, and gives the elevation of the
object in actual size. As he works the potter constantly consults and
measures it. Pieces made in this fashion are known as thrown ware. All
the finest potteries, as well as some of the most expensive
porcelains, are made in this way. However, it is a costly process and
rather slow, for a piece thus shaped must have the entire attention of
a single worker. If we were to make all our china by this method I do
not know where we should bring up. It would take us a decade, and cost
us a great deal of money. But by this means the most artistic results
are obtained. It was in this fashion that the Greeks modeled their
matchless vases, and you can now see why no two of them were
alike. Each potter put his soul into the thing he was making, and as
he had endless time at his command he worked with utmost care to
perfect his product. This was all very well in a warm country where
life was simple; demands few; and where there was not the tension of
present day living. It was a matter of no concern if the artist made
only a few such vases in a lifetime. He had the patronage of the rich,
and was sure of being taken care of. But to-day, alas, we face a
different problem."
[Illustration: "IT IS A COSTLY PROCESS, AND RATHER SLOW"]
"We surely do," agreed Theo.
"Therefore, here in America only a small proportion of this thrown
ware is made. Such art potteries as the Roferno and Sicardo wares,
seen chiefly in private collections and museums, are thrown; also some
of the Grueby, Rookwood, and Cincinnati varieties--all very beautiful
American potteries. In addition to these exquisite home products The
Dedham and Paul Revere potteries made near Boston should be mentioned,
for although of less costly type they are doing much to set a standard
of perfection of form, choiceness of coloring, and fitness of
design. All these wares are distinct contributions to the art
world. Of course certain wares are made by a modification of this
throwing process. Large pieces, for example, frequently have to be
thrown in several parts, fastened together, and afterward
finished. Some pieces the thrower shapes over a plaster-of-Paris
mould; and some he shapes inside the mould, reversing the process and
pressing the clay against its confining surface. The danger in thrown
ware comes from an uneven pressure on the clay resulting in a lack of
solidity; the pieces are not always equally firm at all points and in
consequence sometimes crack."
"Can pieces of any design be thrown?" inquired Theo.
"No, only round pieces such as cups, mugs, vases, jars, or bowls. In
other words, only circular pieces. Frequently, too, these are only
started by the throwing process and are finished by some other means
such as turning, for example."
"What is turning?" asked Theo.
"Surely you have seen a turning-lathe, Theo," asserted
Mr. Marwood. "Here is a turner just opposite us. You will notice he
has a lathe that goes by steam. The vase on which he is working has
previously been roughly formed on a jigger--a revolving mould over
which a sheet of clay has been pressed and quickly shaped. After such
a piece has been dried to a leather hardness the turner takes it in
its crude and uncompleted state and by running his lathe over it
planes down the surface to a smooth, even thickness. Sometimes, too,
by means of one of these lathes milling-tools are used to cut designs
around the neck or base of the article. The rough edges are then
sponged and before the piece is thoroughly dried handles are put on if
desired. Here in America turning is the process very generally
employed for finishing articles begun by the jiggermen."
"And now about hollow ware--how do they make that?"
"Hollow ware is pressed by hand," answered Mr. Marwood. "The process
is used for pieces that cannot successfully be made by any other
means--such things, for example, as soup-tureens and large covered
dishes. The idea is to press the clay over or into moulds so it will
be the exact shape required. Of course this necessitates the making of
pieces in sections. The two sides of a vase are moulded separately,
for instance; also the bottom. Then the parts are pressed firmly
together and held in place by strings or thongs of leather until
securely joined. Afterward the base is inserted in its proper
place. The inside seams are then leveled and sponged away, and the
mould sent to the drying room. Later it is returned; the outside seams
moistened and smoothed; the moulded handles put on; and the piece is
ready to be decorated and fired. It is a difficult ware to make, for
unless the workmen are skilled at giving the clay an even pressure it
is liable to be thicker in some places than others. Sometimes, too, if
the seams are not strongly united the article will crack. It demands a
strong, even touch. Remember that hollow ware is pressed from the
outside; and that flat ware is just the opposite, and is pressed from
the inside. The top surfaces of such things as plates, platters and
trays are thus formed, their outer side being shaped by hand or by a
jolly, which we shall see presently."
Mr. Marwood passed on through the crowded room until he suddenly
paused beside a workman at another machine.
"This," explained Theo's conductor, "is a jigger. There are two
machines very commonly used in the United States for shaping the
cheaper wares: one is a jigger, a device of this type; and the other a
jolly, an invention very similar in construction but having a tool
attached that forms the outside, or bottom of the piece, the inside of
which has previously been shaped by the jigger. You may recall that I
spoke of the jigger; and told you how a revolving mould was inserted
into it, and how afterward a sheet of clay was laid on the outside of
this mould and rapidly shaped. The jolly, on the other hand, is used
for making such things as covers, the top surface of which has already
been moulded. The profile set in the jolly-lever makes the
bottom. That, as I told you, is how we get the base of our plates. For
certain articles the jigger is preferred; for certain others the
jolly; but the aim of both is the same, and the workers at the
machines are all called jiggermen. After an article is taken from the
jigger or jolly it is dried and carried to the turning-lathe to have
its surface smoothed and finished."
"And does it take all these men to run a jigger?" whispered Theo,
pointing to the moving figures that hurried to and fro.
"An organized group of men is employed at each machine," answered
Mr. Marwood. "First there is the _clay-carrier_, who must bring the
material to the workmen; then there is a second man called the
_batter-out_ who takes from the carrier the piece of clay cut into the
proper size, and after laying this on a block gives it a strong blow
with a plaster-of-Paris bat to flatten it for the jiggerman. When
making simple objects such a man can give the article quite a start
even with one stroke. You can see that some such beginning must be
made before the jiggermen can handle the material."
"How much does the bat weigh?" demanded Theo, instantly interested.
"About fifteen pounds. It is not very heavy, but the batter wields it
with considerable force. After the article has thus been
approximately shaped, and the jiggerman has completed it, a
mould-runner must carry the freshly modeled piece to the stove-room to
be dried; and on his backward trip bring with him two other articles
that are already dry. These he takes off the moulds, leaving the dry
piece to go to the finisher, and the mould to the batter-out. The
fourth man in the team, or crew, is the _finisher_. His duty is to
smooth the rough edges of each article with a damp sponge, or a tool
of flat steel. After this process is completed the jiggerman's
crew is through with its part of the work and the goods go to the
greenroom to be counted, and if perfect accepted by the foreman. Most
jiggermen hire their own helpers, as it is simpler for them to do
so. Formerly only round articles were made by the jiggermen--such
things as cups, plates, bowls, etc. But now oval, as well as round
dishes, can be made on a jigger, although elliptical wares are not
turned out this way to any very great extent, other processes of
shaping being preferred for objects of this type."
"You spoke, Mr. Marwood, of casting some wares," remarked Theo.
The older man smiled.
"You have a good memory, my boy," he said. "I did mention casting. It
is an independent process, and shapes of great variety can be
fashioned as well as ornamented in this way. By the casting method,
too, we are certain of getting articles of uniform thickness. We can
even make very thin objects by this means. But the process is
destructive of moulds, and therefore has its flaws. The success of the
plan is entirely dependent on the mould's absorption of the moisture
in the clay; otherwise the method of casting could not be applied to
potteries or porcelains. As the clay is compressed the water is
squeezed out of it, and this the mould must take up, or the clay would
never dry and retain its shape. You can understand that, I think."
"Yes, sir."
"The last of the processes of which I wish to tell you is
die-pressing. Here we take a very finely ground clay dust; moisten it
a little; and fill a die, or steel mould, with it. This die we then
put into a screw, or hydraulic press, and squeeze it under an intense
pressure with the result that the piece is shaped very solidly. We use
this process for making small, complicated objects such as those
employed for electrical purposes. They are brittle and delicate and
have to be manufactured with extreme care."
"Are plumbing supplies made this way?"
"No, indeed! Sanitary pieces are too large to be turned out in such a
fashion. They are made by hand, being first built up inside enormous
moulds. We can employ only the most skilful workmen on this task
because the goods are difficult to make. Such a thing as a porcelain
bath-tub involves a great deal of clay, and therefore were it to be
damaged we should lose much expensive material." Mr. Marwood took out
his watch. "Now, there you have all the various ways of shaping clay
ware! Its decoration and firing is another story, and far too long a
one for us to attack to-day. We must be back at the conservatory at
one o'clock for luncheon. Evidently Mr. Croyden got too deeply snowed
under to join us, so we shall have to hunt him up. Confess you are
hungry."
Theo's eyes twinkled.
"I believe I could eat something if I were urged," he admitted.
"So could I," rejoined Mr. Marwood heartily. "I am starved. We will
find Mr. Croyden right away. It has been a good morning, hasn't it,
Theo?"
"Certainly I've enjoyed it," exclaimed Theo.
"And I too," agreed the older man.
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