This section is from the book "The Boy Mechanic Vol. 2 1000 Things for Boys to Do", by Popular Mechanics Co.. Also available from Amazon: The Boy Mechanic, Vol2: 1000 Things for Boys to Do.
This adaptation of an ordinary iron rake for use on a lawn was the outcome of not having a lawn rake at hand. Two spools, each 1 1/2 in. in diameter, were procured and one forced on each end tooth of the rake. The spools were forced on the teeth just far enough to allow the rake to slide on the ground and prevent the other teeth from digging out the grass. The end of the spools may be rounded and smoothed so that they will slide easily on the ground. - Contributed by H. E. Gray, Montclair, N. J.
Ill: The Spools Prevent the Teeth from Injuring the Grass Roots as the Rake Passes over the Ground