od had been passing through the
factory and going from one building to another; now they entered the
decorating department.

"First I want you to see our air-brush process," Mr. Marwood said.

He led the way to an ingenious machine which by means of compressed
air was spraying a fine jet of color over the surface of a porcelain
plate. In some places this color rippled away into a faint tint; in
others it settled into an area of a deep rich tone. By the aid of
stencils the effect produced was of an exquisitely shaded ware, and
Theo watched the work with delight.

"I think this air-brush process is the most interesting one I have
seen," the boy cried.

"It certainly is fascinating to watch, isn't it?" agreed
Mr. Marwood. "I could stand here all day; but I fear we must go on,
for we still have much to see. Let us go over to where those girls are
gilding. Some of them are putting a fine gold line on the china, and
others are doing elaborate designs in gold. The work of the next group
is to gild the handles of cups and dishes."

They passed on and stood beside the workers.

"That does not look like gold!" exclaimed Theo, who viewed in
astonishment the chocolate brown pigment that the girls were using.

Mr. Marwood laughed.

"All gold looks like that," he said, "before it is fired and
burnished. In fact, all the mineral colors used to decorate glass,
pottery, and porcelain look very different when they are put on from
what they do after they have been subjected to the heat. That is the
wonderful part of working in oxides and metallic colors. The beautiful
hues we see on china or glass are the result of years of
experiment. Never forget that. All china decorators have constantly to
bear in mind the effect of a high temperature upon their colors. What
would be attractive on the unfired clay might emerge from the kiln a
very ugly product indeed. We must reckon on this fact."

Theo nodded.

"It must make the decoration of china a great problem," he said.

"It does. However, decorators have now learned pretty well what to
expect. A certain carmine, for example, fires out violet. Many other
shades fire lighter or darker than when applied, and allowance must be
made for them. The girls who paint china become very skilful in
estimating the changes in colors. These who are working beside us are
doing the finest sort of porcelain decoration--faces, figures, and
flowers. Those across the aisle are doing a vastly different