Audiolibro: Scientific American Supplement, No. 446, July 19, 1884

The Scientific American may be the oldest continuously published periodical in the United States, havinge launched its first publication in 1845. It has been a mainstay of popular science with in depth articles across a broad spectrum of scientific fields. In this supplement are short articles ranging through such topics as Pneumatic Malting, Improved Hay-Rope Machine, Automatic Fast Speed Telegraphy, and Tin in Canned Foods Our Servants, The Microbes - Summary by Larry Wilson