Since Newton"s time many have proposed that gravitation arises from the absorption by material bodies of minute particles or waves filling space. Such absorption would cause bodies to be pushed into each other"s shadows. The principal early proponent of this idea was Georges-Louis Le Sage. The essays in this book explore the remarkable three hundred year saga of Le Sage"s theory, gravitational shielding and the experiments of Q. Majorana, and new and recent Le Sage Models.