The Secrets of the Striations of Cantian C

[John Conduitt]

I've posted a fair few of these 'earliest British coins' before - from the Thurrock potins to Cantian D angular bulls and Cantian E dump potins. They're fun to collect because of the progressive abstraction on both sides - the obverse goes from the head of Apollo to a circle with a large nipple in the middle, while the reverse goes from a butting bull to a set of swings.

This coin comes from the gap between the earlier, chunkier Thurrock potins and the thin, abstract Cantian Ds. It looks much like a Cantian D except the bull is a little more recognisable as some sort of animal. But what's interesting about these are the striations in the fields. As well as progressive abstraction, these coins show the progression of the technology used to make them.

Cantian C Crossed Striations Potin, 100-90BC

Cantii tribe, Kent. Potin, 18mm, 1.57g. Celticised head of Apollo left with ring-and-pellet motif in centre of head; equally-thin striations at 90 degree angles in fields. Celticised bull made up of curved lines, charging left (ABC 153; VA 112-01).

These were cast, and according the Van Arsdell, "the pattern (of striations) was produced by textile, pressed into the clay (for the mould) to produce the cavity system (into which they would pour the metal)". Judging by the various phases the coins went through, there was a lot of experimentation trying to get the design to show as intended, to reduce waste and to make the process fast enough to meet production requirements.

Within Cantian C there are a few techniques evident in trying to get the surfaces of the two mould halves flat so they would sit snugly together and avoid flash (excess metal at the ends) without destroying the design. The types are categorised by the appearance of the striations:

- Crossed striations - textile pressed into the clay to create the cavities and runners (as above).
- Medium striations - moulds produced by cutting a block of clay in two with a wire, which ensured the halves mated perfectly, but caused severe striations that interferred with the design.
- Heavy striations - broad but shallow, usually on one side. Produced by wood pressed against the clay to smooth it.
- Thin striations - on one side. The clay was smoothed with a scraper or knife.

None of these methods worked well, which is why they progressed to Cantian D.