Wednesday, 29 July 2026
08 / About 90 seconds
THE SECURITY TRICK
The ‘radioactive cheque’ was a machine-readable key.
Tiny traces of carbon-14 identified the voucher so the machine could match it to a four-digit PIN. The paper carried the proof, and the machine consumed it after paying out.
That is the delicious tension inside the first cash machine: cash became available after hours before a machine could see your account. The cash was automatic; the relationship was still paper.
WHY ENFIELD?
Barclays chose a building that made a good laboratory.
4CUSTOMER MIX · PAVEMENT · WINDOWS · HEAD OFFICE
See the official listing →
TODAY’S DESERVING CAUSE · RAINBOW ROGUES
Help before ‘not bad enough’ becomes a crisis.
£25FUNDS ONE HOUR OF FAMILY SUPPORT
Rainbow Rogues’ Access Without Barriers Fund in Scotland backs inclusive family support without a diagnosis and open-access community counselling without statutory thresholds or long waits.
THURSDAY IN WONDERFUL DAILY
The PIN patent came before the cash machine.
Thursday: how Paisley engineer James Goodfellow filed a card-and-secret-number patent in May 1966 (13 months before Enfield’s opening) and why invention credit still gets tangled.