Plate, draft of figure 12 showing double platinum and iron wire by [William Thomson] Early draft of figure 12, incorporated within text, showing a double platinum and iron wire with copper attached to the ends of the iron wire. A later version is found at PT/55/1/34. Subject: Physics Published in Philosophical Transactions as 'The Bakerian lecture.-On the electro-dynamic qualities of metals'. Received and read by the Royal Society on 29 February 1856. [1856]