magneto-electric machine (Gramme) (1877) gas power engine (Lenoir) hot water system (Perkin) Leyden elements Ruhmkorff elements influence machine (Holz) Water pressing and sucking machine (Bunsen) projection apparatus (Drumond's light) microscopes galvanometers heliostat centrifugal machine (Jahr) [centrifuge] large kymograph (Hering) respiration apparatus steam drying apparatus air drying apparatus air pumps cathetometer balances multiplicator