Balloon Locomotive Correspondence Haenlein

Paul Haenlein (1835–1905) was a German engineer and flight pioneer. Haenlein studied at Technische Hochschule in Karlsruhe and received his education as a mechanical engineer and pattern maker. While working as a civil engineer for different German factories, he created a dirigible airship which was powered by an internal combustion engine. In 1869, Haenlein contacted Charles Francis Adams, U. S. minister to the Court of St. James's (United Kingdom), asking him to share his balloon locomotive plans with the U. S. government in hopes of selling his invention for military purposes. In 1872 Haenlein obtained a U. S. patent (No. 130 915) "Improvement in Balloon-Locomotives" to use the otherwise wasted gas in the dirigible's engines for propelling power as well as ascending.