on, as he gazed at the three prints, in line and
spaced as a walker's would be. Their guide said that there had been six,
but the other three had fallen after being exposed to the air.

"I wish it hadn't been such a muddy day," sighed Ethel Blue. "The mud
squeezed around so that his toe marks were filled right up."

"It certainly was a muddy day," agreed Roger, "but I'm glad it was. If
he had been walking on rocks we never should have known that he had
passed this way a million or so years ago."

They were all so filled with interest that they were almost unwilling to
go on in the afternoon, although Mr. Emerson promised them other sights
around Uniontown, quite different from any they had seen yet.

It was late in the afternoon when they ferried across the river in a
boat running on a chain, and took the train for the seat of Fayette
County. As the daylight waned they found themselves travelling through a
country lighted by a glare that seemed to spread through the atmosphere
and to be reflected back from the clouds and sky.

"What is it?" Dicky almost whimpered, as he snuggled closer to his
mother.

"Ask Grandfather," returned Mrs. Morton.

"It's the glare from the coke ovens," answered Mr. Emerson. "Do you see
those long rows of bee-hives? Those are ovens in which soft coal is
being burned so that a certain ingredient called bitumen may be driven
off from it. What is left after that is done is a substance that looks
somewhat like a dry, sponge if that were gray and hard. It burns with a
very hot flame and is invaluable in the smelting of iron and the making
of steel."

"That's why they make so much here," guessed Ethel Brown, who had been
counting the ovens and was well up in the hundreds with plenty more in
sight. "Here is where they make most of the iron and steel in the United
States and they have to have coke for it."

"And you notice how conveniently the coal beds lie to the iron mines?
Nature followed an efficiency program, didn't she?" laughed Roger.

"They turn out about twenty million tons of coke a year just around
here," Helen read from her guidebook, "and it is one of the two greatest
coke burning regions of the world!"

"Where's the other?"

"In the neighborhood of Durham, England."

"It is a wonderful sight!" exclaimed Ethel Blue. "I never knew fire
could be so wonderful and so different!"

Mr. Emerson's search for Stanley Clark seemed to be a stern chase and
consequently a long one. He