With reference to “The Things They Say” on page 560 of your June issue. The “mythical” glass-balancing trick is not one of the apocryphal Rolls-Royce stories but fact, and was used in their sales literature. I have before me a facsimile of a Rolls-Royce sales brochure of around 1913 and I quote: “…With a view to proving in a conclusive manner the extraordinarily perfect balance of the six-cylinder Rolls-Royce engine (a perfection never previously attained in any internal combustion engine) the Rolls-Royce Company carried out the following tests. The experiments, which were carried out in the presence of well-known experts and journalists, were the most severe tests for vibration that could be devised.
“Three glass tumblers were balanced upon the bonnet of a six cylinder 40/50-h.p. Rolls-Royce, these tumblers were then filled to overflowing with water, coloured with red, green and black ink respectively. The engine was started, the starting handle removed, and a revolution counter put on the front end of the crankshaft. A photograph was then taken of the glasses, an exposure of exactly four minutes being given, during which the engine revolved 4,600 times at 1,150 revolutions per minute. The experiment was repeated and, notwithstanding the glasses having been previously filled to the utmost, not a drop of liquid was spilled from them at any time, and the sharpness of the outlines in the photograph shows the absence of vibration in a most conclusive manner…”
The text then goes on to describe a penny balancing on edge on the radiator cap for two minutes.
The accompanying photograph shows that one side of the bonnet was raised for this experiment and the glasses placed on the underside of what would be the top of the bonnet in its normal closed position.
Let us not deride all the old R.-R. stories!
[With the bonnet raised on one side this would certainly be possible.—Ed.]