Between 1850 and 1950, most electronics used glass vacuum tubes, such a cathode ray tubes (CRT). Henk Dijkstra has an extensive collection of such tubes on 28 pages, with the history behind them. Pictured is a liquid-filled Geissler tube, designed by Johann Heinrich Wilhelm Geissler in Germany in the early 20th century. Link -via Everlasting Blort
They look pretty cool.
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