d the metals would melt and discolor your
porcelain. Sometimes this happens with cheap chinas. I dare say you
yourself have seen dishes that are specked with yellow, or have stains
here and there. Sometimes you can also detect bluish particles. That
means the cobalt has not been properly ground or sifted. In less
expensive wares such defects are frequent. But there is no excuse for
them when making fine quality porcelains."

Theo listened attentively.

"After this iron has been extracted," went on Mr. Marwood, "the slip
passes into smooth agitators, where it is simply kept well stirred in
order that the heavier ingredients in it may not settle to the
bottom. Then the liquid is forced by means of a slip-pump into the
filter-presses, and it is now that you begin to see an approach to the
clay used for shaping dishes. Up to this point the slip has been only
a thick creamy substance. Now the filter-press squeezes this through
canvas bags until after having been pressed between iron plates you
get your cakes of smoothly mixed clay of about the consistency of
putty. Each cake is of regulation size, and it is supposed to be an
inch-and-a-quarter in thickness, and to weigh forty-two pounds."

"The clay is now ready for use?" Theo asked.

"Practically so," was Mr. Marwood's reply, "although before it can be
sent to the jiggermen to be modeled it must pass through the pug-mill
to be made more plastic and workable. It is here that it gets its
final kneading, all the air bubbles in it being eliminated by a series
of steel knives."

"I must say it is pretty thoroughly prepared," smiled Theo.

"It has to be," was Mr. Marwood's grave reply. "Each of these details
is an important factor in the making of high grade porcelain, and
should any of them be omitted we should get no flawless ware. It was
this infinite care in preparing clay that gave to China, Japan,
France, and Germany their perfect results in porcelain-making. If we
would equal what has been done in the past we must be just as
painstaking, and neglect no detail. As a nation we Americans are far
too prone to dash ahead and expect results all in a minute. We do not
like to mount a stairway step by step; we wish to shoot to the top in
an elevator. Now you cannot manufacture porcelain, or for that matter
anything else, in such a fashion."

"I know it," replied Theo. "Dad says we hurry so much over the little
things that we turn out quantities of poorly made goods that ar