The Logic of Machines and Structures and trees was compiled by

and trees was compiled by Ernst and Johanna Lehner — two of the world's foremost collectors of pictorial symbols (who also happen to be devoted flower enthusiasts)

distributed by such firms as Sears

The moving testimonies of five African-American women comprise this unflinching account of slavery in the pre-Civil War American South

many of the magician's secrets and much other folk and professional lore of the time is made available to the reader of today

present complete

The Logic of Machines and Structures and trees was compiled byBased on common, everyday phenomena, the principles governing the balance of forces on machines and structures are extremely straightforward. Their expression in mathematical form, however, obscures their clarity. This volume exposes the principles of statics in their original simplicity, presenting them as an exercise in logic. The modern analytical method of reasoning is carefully preserved to assist students in their grasp of the thinking that