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).
To Mr. Royce clarifying the taxation of petrol engines with a comparative table of taxes for various engine bore sizes.
| Identifier | ExFiles\Box 76\1\ scan0001 | |
| Date | 7th July 1910 | |
| R.R. 935A (100H) (M 96. 24.2.10) E.P. 6127. X627 7th July 1910 Mr. Royce. Re Taxation of Petrol Engines. It occurs to me that I may have misunderstood you with regard to the bore that you wished to be compared (for taxation) with 100 m/m.{Mr Moon / Mr Moore} The information I gave you referred to a comparison between our standard 4½" bore and the proposed 100 m/m bore. To make the matter clear I have tabulated the taxes for the bores that interest us. | No. of cyls | 2 | 6 | 6 | 4 | 4 | 3 | 3 | 2 | 2 | 6 | |---|---|---|---|---|---|---|---|---|---|---| | Bore | 3¾" | 100 m/m | 4" | 100 m/m | 4" | 100 m/m | 4" | 100 m/m | 4" | 4½" | | H.P. (RAC) | 11.2 | 37.2 | 38.7 | 24.8 | 25.8 | 18.6 | 19.35 | 12.4 | 12.9 | 48.3 | | Tax. | £3/3s. | £10/10s | £10/10s | £6/6s. | £6/6s. | £6/6s. | £6/6s. | £4/4s. | £4/4s. | £21. | | Max. bore for this tax. | 3¾" | 4 7/16" | 4 7/16" | 4" | 4" | 4 5/8" | 4 5/8" | 4 7/16" | 4 7/16" | 5" | | ||