Dr Brian Austin who served in the S.A.C.S between 1963 and 1984 remarked from West Kirby, England, as follows:
Establishment of the S.A.C.S.
“... the SACS came into being on 01/11/1923 with Col Edward Arthur Sturman as Director of Signals. He was, in fact, the Postmaster General so he wore two hats, one at the GPO and the other, as a part-
Origin of the title ‘Jimmy’
When Dr Austin saw Andy Malan's query about the Signals emblem and stated the following in this shortened version:
“The Jimmy dates back to the earliest days of the Royal Corps of Signals of the British Army. The personage who bears the name of Jimmy is actually Hermes, the Greek messenger of the gods, or Mercury, his Roman counterpart, though it was suggested by some that Mercury was actually the God of Commerce and Industry, which adds a rather interesting new dimension to the art of military signalling.
Why he should be called Jimmy is itself interesting. Evidently, in 1926, when the founding fathers of the Royal Corps of Signals (established in 1920) were discussing the matter of the emblem and also whether to refer to him as Hermes or Mercury, one member of the committee suggested naming him Jimmy after the Corps boxing champion, Sgt Jimmy Emblem! The idea appealed to those around the table, so ‘Jimmy’ became the name that has ever since referred to the bearer of messages within the British Army and all those Signals Corps of the Commonwealth that adopted this legendary figure as their emblem.
There are some differences between the Jimmy of the S.A.C.S. and those others. For example the S.A.C.S. version has no crown suspended in the feather above his head. It disappeared in after 1948, while our Jimmy also carries what appears to be a flask in his raised right hand. It is sometimes referred to as a ‘message flask’, though Walter Volker in his excellent account of the Corps history calls it a traveller's purse. Our S.A.C.S. Jimmy is based on a statue carved by the Italian sculptor Giovanni da Bologna in 1564 and housed in the Pitti Palace in Florence. Jimmy stands on a scroll bearing the Corps motto ‘Certa Cito’, which means Swift and Sure. The letters SA for South Africa appear either side the foot that balances upon the globe of the earth with a wreath below it.
Most of the Commonwealth Corps have the name of the country below the scroll and wreath. In South Africa's case the need for bilingualism would have made South Africa/Suid Afrika rather cumbersome, hence SA sufficed.