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).
The utility of an accelerometer for testing car performance on gradients compared to a recording Barograph.
| Identifier | ExFiles\Box 113\2\ scan0015 | |
| Date | 14th November 1922 guessed | |
| -2- recording Barograph. In the former, an isolated observation loses more than half its value because its position with regard to the preceding and following readings is in no way indicated. The latter, however, by means of its continuous curve, enables the observer instantaneously to compute the relative value of any particular point. Mr. Wimperis states as a valuable property of his instrument, that it will show the amount of power any car has in hand when climbing a gradient, i.e. - the gradient of the hill the car could actually climb. With a careful selection of hills, this is probably true, but in a county like Derbyshire, hills can equally easily be selected which the car will just climb and will not climb on 2nd., this giving a definite positive and negative result, while on bottom, though it may not be possible to locate gradients which will stall the car, the accelerometer is of little value as it only reads up to gradients of 1 in 4, an acclivity which it is obvious the Goshawk will climb easily, given a reasonable surface. As a measure of the comparative values of tractive resistance of similar cars by testers, I think the instrument would be useful provided these resistances vary considerably and a rapid and accurate method of installing the instrument on the car could be devised. I do not, however, think it is going to be of great value to the experimental. As my practical experience of the instrument is limited to one day on the road, the value of these comments is distinctly questionable. Rm.{William Robotham - Chief Engineer} | ||