Roland King-Farlow’s letter describing the clutchless state of Peter Hampton’s t 903 60-h.p. Mercedes when it was resurrected in the early 1930s, prompts me to ask whether any Motor Sport reader can say when and why the term “scroll clutch” was coined? Early descriptions of Mercedes cars in the motor journals refer to the “coil-spring clutch”, or “spring coil clutch”, both of which come near enough to the maker’s own name of “federbandkupplung“. This translates literally as “spring ribbon coupling” I suppose, though the nearest my little German dictionary goes towards “kupplung” is to give “kuppler” as a pander and “kupplerin” as a procuress. The German for “scroll” is “Rolle“, and I do not think the term “scroll clutch” came into use until long after the device itself was obsolete.

Motor-nomenclature is often pretty odd and misleading, and sometimes incorrect in the use of engineering terms, as with “tachometer” or “rev counter” for “engine speed indicator’: a revolution counter is a recording device, not a speed indicator, and a tachometer is a speed indicator but not necessarily an engine speed indicator. Much of the trouble arises from misuse of foreign terms, as Mervyn O’Gorman wrote in 1905 of the cardan joint: “The Original inventor was the notable English physicist, Robert Hooke, and the joint is usually called Hooke’s joint, save in motoring circles where it is fashionable to suppose that every such device must be called by a French name before it can be expected to work.”

Portbridge Anthony Bird.