“Certainly,” said Hal, with freezing politeness, taking hold of the gee-pole with one hand and swinging his whip from the other. “Mush!” he shouted. “Mush on there!”

The dogs sprang against the breast-bands, strained hard for a few moments, then relaxed. They were unable to move the sled.

“The lazy brutes, I’ll show them,” he cried, preparing to lash out at them with the whip.

But Mercedes interfered, crying, “Oh, Hal, you mustn’t,” as she caught hold of the whip and wrenched it from him. “The poor dears! Now you must promise you won’t be harsh with them for the rest of the trip, or I won’t go a step.”

“Precious lot you know about dogs,” her brother sneered; “and I wish you’d leave me alone. They’re lazy, I tell you, and you’ve got to whip them to get anything out of them. That’s their way. You ask anyone. Ask one of those men.”