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.
A wood screw having the threads hammered flat on two sides can be easily driven in with the flattened sides parallel to the grain of the wood. When the screw is turned a quarter turn the remaining threads cross the grain and hold as well as if they had been turned in all the way. This is an especial advantage where something is wanted vhich is easily inserted and will hold better than a nail. - Contributed by P. D. Merrill, Chicago.