Then he picked out some pots, set them side by side on a table, and measured them to see how long a row they made. Then he changed them and measured again.
"There," he said, "those will just fit one window. Now, another set for the other window and we are ready for the soil."
"Where will you get dirt? Everything is frozen hard," said Davy.
The Chief Gardener took up a spading-fork from among the tools.
"We'll get our hats and coats, first," he said, "then we'll see what we can find."
Outside it was really very cold, but the children, with their thick wraps, did not mind. They raced in the snow across the empty little garden, and followed the Chief Gardener to a small mound in one corner. Here he pushed away the snow, and with the fork lifted up a layer of frozen-looking weeds; then another layer, not quite so frozen and not quite so weedy; then still another layer that did not seem at all frozen, but was just a mass of damp leaves and bits of grass. And under this layer it must have been quite warm, for steam began to rise white in the cold air.
"Oh, see!" said Prue. "What makes the smoke?"
"That's steam," said Davy, wisely; "but what makes it warm?"