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).
Letter from The Morgan Crucible Company discussing the analysis and comparison of different brush samples.
| Identifier | ExFiles\Box 166\1\ img042 | |
| Date | 8th December 1934 | |
| TT 4109 CODES, ABC 4th, 5th & 6th (5 LETTER) EDITIONS. A.I. LIEBERS & WESTERN UNION (UNIV. & 5 LETTER EDIT) & BENTLEYS. Inland Telegraphic Address. "CRUCIBLE, PHONE, LONDON" (2 words only chargeable) Cable Address. "CRUCIBLE, LONDON" Telephone No BATTERSEA 2250. THE MORGAN CRUCIBLE COMPANY LIMITED BATTERSEA WORKS, CHURCH ROAD, LONDON, S.W.11. MORGANITE TRADE MARK IN REPLY PLEASE REFER TO Z DEPT. Zk/RR 8th December, 1934. Messrs. Rolls-Royce Ltd., WST D E R B Y. Dear Sirs, Your letter of the 1st instant, Ref. Hs{Lord Ernest Hives - Chair}/Wst.1/MA, together with sample brush, has been receiving our attention. From an examination of the sample marked 4503 we find this is of a copper carbon class, as distinct from the copper graphite composition of Link CM5H and is harder. It is possible that the brush pressure was originally set to give the most favourable "life" with the American brush but is too heavy for the Link CM5H and that if lowered, Link CM5H might attain the performance given by the American brush under existing conditions. We have a quality of the same composition as Link CM5H but of the same hardness as the American brush, namely, CM8121, and shall be pleased to make up some brushes for you to test if you will well let us know how many you require for the purpose. We confirm that the contact drop of Link CM6 is lower than that of CM5H. Although of approximately the same copper content, the texture of Link CM6 is such as to give it | ||