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).
Experiment No. 391, testing the Michelin 'Perda' Jack on colonial axles with various wheel sizes.
| Identifier | ExFiles\Box 26\3\ Scan003 | |
| Date | 17th June 1913 | |
| From Exp. Dept. Copies for: Mr Johnson. Mr Royce. Mr Spinney. Mr Nadin. Report on Experiment No. 391 Michelin Jack "Perda" I have had this Jack tried under colonial axles as requested and find that it is quite satisfactory in its range for the front axles both with 895 X 135 and 935 X 135 wheels. It is just suitable for use under back axle with 895 X 135 wheels but will not extend enough to satisfactorily lift 935 m/m wheels clear enough of the ground. It would be suitable if a packing, say a block of wood 4" thick were used when lifting a back wheel. | ||