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 G. Cussons, Ltd. discussing the placement, features, and production of the Dalby Watson Optical Indicator.
| Identifier | ExFiles\Box 79\3\ scan0049 | |
| Date | 27th September 1918 | |
| X 3181 Telephone : 6991 City, Manchester. Reference G.{Mr Griffiths - Chief Accountant / Mr Gnapp} CUSSONS, Ltd., The Technical Works, LOWER BROUGHTON, MANCHESTER, :: LONDON OFFICE and SHOWROOM :: Thanet House - 231 Strand (opposite the Law Courts). Manufacturers of Technical and Scientific Apparatus. Your Ref. EFC3/T24918 Ours F.190/3. 27th. Sept. 1918. [STAMP: RECEIVED S.D. 28 SEP 1918 P] Messrs. Rolls-Royce, Ltd., Nightingale Road., Derby. Re Dalby Watson Optical Indicator. Dear Sirs, Replying to your letter of the 24th. under above reference, we beg to say that any type of petrol engine indicator, should be placed as closely as possible to the engine cylinder, in order, (1) to prevent additional clearance volume error, (2) to obviate secondary explosions in the connecting pipe, (3) to reduce the gas inertia error to which you refer. The earlier troubles with the diaphragm have been overcome, and with the present arrangement, with its water cooling jacket and the special steel and method of making employed for the diaphragm, there is practically no trouble. This is indeed one of the leading features of the present instrument. The vibrations in the pipe, have been stopped by altering the form of the pressure chamber, but it is advisable to reduce connections to as short as possible, in order to prevent time-lag and clearance errors. We are now actually working on a number of Indicators and hope to be able to write you definitely as to delivery towards the end of October. Yours faithfully, G.{Mr Griffiths - Chief Accountant / Mr Gnapp} Cussons Ltd. Geo. W. Cussons AWARDED GOLD MEDALS, and GRAND PRIX for TECHNICAL APPARATUS for SCHOOLS and COLLEGES. | ||