[Article] War inventions that came too late Adjust Share By Frank Parker Stockbridge, This article is only available as a PDF to subscribers. Download PDF Tags 20th century Balloon gases Caterpillar tractors Drone aircraft Gases, Asphyxiating and poisonous Helium Inventions Technology United States War use World War I, 1914-1918 More from Frank Parker Stockbridge Cargoes through the clouds Adjust Share Close < Previous Issue | View All Issues | Next Issue > November 1919 < Previous Issue | View All Issues | Next Issue > Table of Contents Close