"AYRTON-MATHER / GALVANOMETER. / PATENT." "ROBT.W. PAUL. LONDON.N." Binnen in de behuizing:"N 676." "L 444"
Beschrijving
Formaat
Hoogte: 20 cm Diameter: 18 cm
Documentatie
John T. Stock & Denys Vaughan, The development of instruments to measure electric current (Science Museum, 1983, BOERH 14.688 cat) p. 25-26, over Fa. Paul: 28 en 45