From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Sourcing and specifications of half-watt lamps from the Ediswan Company.
| Identifier | ExFiles\Box 38\3\ Scan285 | |
| Date | 20th January 1921 | |
| R.H. & A.{Mr Adams} (100 T) (S.H. 768, 10-12-20) G.{Mr Griffiths - Chief Accountant / Mr Gnapp} 1947 To R.{Sir Henry Royce} from EFC. c. to CJ. c. to E.{Mr Elliott - Chief Engineer} X 3362 EFC1/T20.1.21. X. 3362 - LIGHTING INSTALLATION AT W.W. X.1114 We have to-day received a letter from the Ediswan Company in answer to an enquiry put to them in connection with your R9/G7.1.21. They apologise for having incorrectly quoted us that they could supply 12 volt half watt lamps for 22.c.p. Such lamps were therefore ordered and although we tested these before sending them to you, we did not notice that they were 24 watt, but assumed that they were 22 c.p. It now transpires that these are the lowest c.p. 12 volt half watt lamps that the Ediswan Co. manufacture. You may remember that we informed you in our EFC7/T19.9.19 that we had made enquiries at that time of (a) The Ediswan Company (b) The General Electric Co. (c) The B.T.H. Company. as to whether they could supply smaller wattages than 24 in 12 volt half watt lamps, but each of these stated that they could not. So far as we know, this position is not altered today. It therefore becomes doubtful if we can obtain 24 volt half watt lamps of less than 48 watts. I have, however, a 24 volt half watt lamp of a much larger size bulb and large size holder in my kitchen and I will measure the current of this and find out if this is 24 or 48 watt. On second thoughts I am inclined to think it is only a 1 ampere lamp. We are, however, having the necessary enquiries Contd. | ||