Some of the men are stationed along the shores to prevent the logs from lodging or floating into bays or setbacks.

Some stand at the heads of bars or islands, where with pike poles they shove off the logs that might stop there and form a jam; others follow "sacking the rear" to clean out such logs as may have become stranded.

This "sacking the rear" takes most of the time, Fig.16.While "on the drive" men often work fourteen hours a day, a good part of the time up to their waists in ice water.

Their boots are shod with "caulks," or spikes, to keep them from slipping on the logs, and they carry either pike poles or peaveys, Fig.17.The latter are similar to cant-hooks, except that they have sharp pikes at their ends.

So armed, they have to "ride any kind of a log in any water, to propel a log by jumping on it, by rolling it squirrel fashion with the feet, by punting it as one would a canoe; to be skilful in pushing, prying, and poling other logs from the quarter deck of the same cranky craft." Altho the logs are carried by the river, they have to be "driven" with amazing skill and bravery.
[Illustration: Fig.17.Log Driving on the Ausable River.] The climax of hardship and courage is reached when a "_jam_" is formed, Fig.18.Sometimes one or two logs are caught in such a way as to be locked or jammed and then soon other logs begin to accumulate behind them, till the whole river is full of a seemingly inextricable mass.