Filings coherer, glass tube formed into T-shape at one end and bent round into U-shape at other end with bulb, 1899 Radio Communication 1899
Filings coherer, glass tube bent at 45-degree angle at one end to form side-pocket, 1898 Radio Communication 1898
Cossor Wurncell W.1 output triode valve (McVitie Weston valve collection), 1923 Electronic Components 1923