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 A. T. Speedometer Co. Ltd. discussing the dynamic balance and concealment of movement on their instruments.
| Identifier | ExFiles\Box 59\2\ Scan227 | |
| Date | 28th August 1933 guessed | |
| A.{Mr Adams} T. SPEEDOMETER CO., LTD. CONTINUATION. 2 Messrs. Rolls-Royce Ltd. matters if we put the "correct" position at your average temperature figure. Another point is whether you take into consideration the "fast reading" on the dial of the A.T. when comparing it with the "Nemag". (2) Dynamic Balance. On the Bentley instruments we noticed one or two, which at these high speeds, were slightly out of balance, but we are quite certain no damage will take place to the instruments because of this, as the two Ball Races are amply large enough. On the other hand, all future instruments will be carefully balanced before despatch to you, and this would have been done on the earlier instruments had there not been such tremendous pressure for delivery. In any case, on the new sample that we are endeavouring to bring through shortly, where the weight is greatly reduced, the amount of revolving matter will be much less, and this query will not arise. (3) Concealment of Movement. The central hole in the A.T. dial has, since its inception many years ago, been a characteristic of the instrument, and we have always had the impression that Messrs. Rolls-Royce Ltd., preferred it. It is, of course, quite easy to close this dial immediately round the canon, leaving only a circular groove in which the hand will work, and upon receipt of your official request to do so, subject to stock, we can quickly take care of this matter. Awaiting your reply, and assuring you always of our best service. We beg to remain, Yours faithfully, For THE A.T. SPEEDOMETER CO.LTD. H R Buckland [Signature] Director. | ||