I’ve enjoyed recent issues of Motor Sport even more than usual and was most interested in the expenences of Mr. J. B. Perrett.
On the subject of “roll centre” I have always believed the term to be attributed to F. H. Royce’s famous assistant Maurice Olley, being a renaming of Dr. Lanchester’s “side location” or “lateral location” which the latter coined around the turn of the century.
Olley was almost certainly using the “rock and photograph” technique for roll axis determination when his wishbone IFS and Dubonnet’s systems were both demonstrated by GM in 1933.
A search of the published papers of the early ’30s would probably resolve the matter and would show people like the Lanchesters, Lavaud, Broulheit, Olley, Bestow, Renwick, Charles, Sampietro and Perrot all contributing papers on to the detailed discussions on papers at that time.
The Proceedings of The Institution of Automobile Engineers certainly make interesting and rewarding reeding “forty years on”.
Foston K. EAMES