At times the whirlwind tore holes under their feet, then again the sand and gravel bounding from the sides of the camels would form, in the twinkling of an eye, mounds reaching to their knees and higher.
"In Desert and Wilderness"
Henryk Sienkiewicz
Nor can we resist the conclusion that the stones were at one time rolled about by the action of water-that being the only mode in which gravel-stones are shaped.
"Geology"
James Geikie
Sand dunes and gravel lines were also piled up, while huge drifts of pressed snow indicated a dangerous atmospheric agitation.
"My Attainment of the Pole"
Frederick A. Cook