The Joanna Tansley Collection of Patterns, Proofs and Coining Trials

Miscellaneous, Trial Blank, possibly for the brass Threepence, in nickel-brass, ici above two wavy lines both sides, edge plain, 18.5mm, 2.46g/12h. Light traces of handling and one side partly toned, otherwise extremely fine and of the highest rarity, the only specimen known to the vendor (£300-500)

This lot was sold as part of a special collection, The Joanna Tansley Collection of Patterns, Proofs and Coining Trials.

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X-ray fluorescence spectrometry by the Royal Mint has confirmed the nickel-brass compsition. The metal for the new nickel-brass threepences of Edward VIII, the first polygonal coin struck for regular circulation in Britain, was supplied to the Royal Mint by ICI Metals Ltd, proprietors of the Kings Norton mint in Birmingham. In the early months of 1936 there was considerable discussion about the weight and thickness of the new coin, the Mint preferring a lightweight piece of about 60 or 70 grains (3.9 to 4.5g), but such a piece could have been used to operate automatic machines and electricity meters designed for sixpences and shillings (Dyer, p.21). Because of this the flan thickness (and consequently the weight) had to be increased to 105 grains (6.8g). The weight and size of this experimental blank might infer that it was produced by ICI Metals early in the gestation period for the coin