Letter from Joseph Lucas Limited discussing the practice of positive versus negative earth systems in American and English cars.
| Identifier | ExFiles\Box 164\4\ img257 | |
| Date | 5th October 1936 | |
| HEAD OFFICES & WORKS: GREAT KING ST. {Capt. P. R. Strong} , BIRMINGHAM. CONTRACTORS TO THE ADMIRALTY, WAR OFFICE, AIR MINISTRY, INDIA(Production 20 HP. with 4-speed box and Front Wheel Brakes) OFFICE, G.P.O. AND LEADING RAILWAYS TRADE MARK JOSEPH LUCAS LIMITED GREAT KING STREET BIRMINGHAM 19 TELEPHONE: NORTHERN 5201 (12 LINES) TELEGRAMS & CABLES: "LUCAS, BIRMINGHAM" 'KING OF THE ROAD' LAMPS, HORNS, 'CYCLEALITIES' 'MOTOR-CYCLEALITIES' 'MOTORALITIES' MAGNETOS, BATTERIES, ELECTRIC LIGHTING & STARTING SYSTEMS Codes: A B C 5th & 6th EDNS & BENTLEY'S 1st & 2nd SERVICE DEPÔTS BELFAST: 3/5, CALVIN STREET, MOUNT POTTINGER BIRMINGHAM, 18: GREAT HAMPTON STREET BRIGHTON, 4: 95, OLD SHOREHAM RD., HOVE BRISTOL: 345, BATH ROAD CARDIFF: 54a, PENARTH ROAD COVENTRY: PRIORY STREET DUBLIN: PORTLAND STREET NORTH, NORTH CIRCULAR ROAD EDINBURGH, 11: 60, STEVENSON RD., GORGIE GLASGOW: 222/228, ST GEORGE'S ROAD LEEDS: 64, ROSEVILLE ROAD SERVICE DEPÔTS LIVERPOOL, 13: 450/456, EDGE LANE LONDON: DORDRECHT ROAD, ACTON VALE, W.3 LONDON: 753/759, HIGH ROAD, LEYTON, E.10 LONDON: 319, REGENT ST. {Capt. P. R. Strong} , W.1. SHOWROOMS & OFFICES LONDON: 155, MERTON ROAD, WANDSWORTH, S.W.18 MANCHESTER, 3: 291/293, DEANSGATE, SUPPLY DEPOT MANCHESTER: TALBOT RD., STRETFORD NEWCASTLE-on-TYNE, 2: 64/66, ST MARY'S PLACE WHEN REPLYING PLEASE REFER TO H.E.West, Esq., Messrs.Rolls-Royce Limited, DERBY. EAW/EE 5th. October 1936. Dear Mr.West, In reply to your letter of the 2nd. I attach list of American cars using positive and negative earth. This was taken from data issued at the end of 1935 and I think possibly one or two more may have gone over to positive earth, since positive earth is a definite recommended S.A.E. practice. As regards English cars, as far as the records go all the 1937 models, with the exception of the Morris range, use positive earth, and I believe Morris will probably change over on their next series. Some of the commercial vehicle users are, however, still retaining negative earth, in those cases where they use an earth return system. As regards the advantages of the positive earth, I think we have already spread ourselves at some little length on this and I am enclosing some notes which we issued some time ago to put forward our point of view, and my own personal feeling is that you will be well advised in coming into line with what is now getting fairly general practice. Yours sincerely, EHWatson Encl: | ||
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).