Grey metal slide projector, on a black bakelite base; with a grey tin cover and a brown leather carry handle, and a film holder with a long lens."Optikotechna Made in Czechoslovakia"projectors, projector components

Probably used at the Ballarat School of Mines as a teaching aid to demonstrate surface wave propagation in liquids.A hollow cast iron base contains electrical components which provide upward illumination of variable frequency. Cover is shaped lile a soup plate, with a 6.5cm diameter lens in the centre. An overhead lens transmits light to an adjustable mirror for viewing from the side. Complet with 240 volt AC lead and plug.scientific instrument