In Inclined Planes, inhabitants of Mammoth Island have decided to smash boulders into bits by dropping them off a wooden tower to make gravel for their new roads. While this method does produce gravel, the islanders find it is difficult and even dangerous to hoist boulders up the side of a tower. A young islander, Olive, suggests that they roll the boulders up a ramp instead of hauling them up the tower, and proves that it takes less effort to roll the boulders up an inclined plane, thereby allowing them to get the job done more easily!