When, as a child of eleven, she had played leapfrog, he could hardly have been more than seven, and she felt herself to be far more than four years his senior now.
"The Story of Louie"
Oliver Onions
How strangely the world has been built, bed after bed of limestone or slate or quartzite, pale grey or pale green or dark red or purple, built into cathedrals or castles, or crumpled like coloured cloths from the rag-bag, squeezed together into arches and troughs, into V's and S's and M's ten miles long and two miles high; or else sheets of rock twenty thousand feet thick have been sliced into blocks and tilted up to play leapfrog with one another.
"Among the Canadian Alps"
Lawrence J. Burpee
leapfrog is one of his methods of getting over the ground quickly.
"McGuffey's Fifth Eclectic Reader"
William Holmes McGuffey