Bramah's challenge lock: a 200-guinea dare that stood for sixty-seven years
The lock in the window at 124 Piccadilly carried a notice in gold letters on black: anyone who could pick it would receive 200 guineas the moment it was done. The notice stayed in that window for fifty years.
Joseph Bramah had walked from a Yorkshire farm to London in 1773, twenty-five years old and ambitious enough to cover the 170 miles on foot. By 1784 he had patented a lock built on a different principle than anything before it. Most locks of the era used iron wards — fixed obstacles a skeleton key or a patient picker could work around. Bramah’s used a cylindrical key with notches of varying depths, each pressing one of eighteen spring-loaded sliders to a precise position; only when every slider aligned correctly could the barrel rotate. Wikipedia tallied the permutations at roughly 470 million. The arithmetic was impressive. The manufacturing was another problem entirely.
Bramah hired Henry Maudslay, a young machinist, to make the tolerances real. The collaboration transformed both men: Maudslay went on to design the screw-cutting lathe that helped mechanize British industry, but in the 1780s his immediate job was making Bramah’s sliders behave at the precision the design demanded.
The challenge lock appeared in the Piccadilly window around 1801: a barrel-shaped padlock sealed in a box, keyhole exposed, and the gold-letter dare. Bramah died in 1814 without anyone collecting. His son continued the business and the notice stayed up. By 1851 the unpicked lock had become a kind of national monument to British ingenuity.
Alfred Charles Hobbs arrived at the Great Exhibition as a sales representative for Day & Newell, a New York firm with a lock of their own to push. His strategy was to demonstrate British vulnerability before offering the alternative. He opened a Chubb Detector lock — the other great English security device — before impressed observers at the Crystal Palace, then went to Piccadilly.
A committee supervised the Bramah attempt. The lock was removed from its window, sealed in a box with only the keyhole exposed, and Hobbs was given thirty days. It took him fifty-one hours spread across sixteen days. He opened it in front of witnesses, and Cabinet Magazine details the newspaper controversy that followed — the British lockmaking establishment disputed the conditions — before arbitrators awarded Hobbs £210, the guinea-equivalent of the original prize.
The British industry responded as a challenge is supposed to make you respond: it improved. Chubb redesigned its Detector. New mechanisms appeared. The Bank of England replaced its locks with Day & Newell’s Parautoptic model — the very lock Hobbs had sailed over to promote.
Hobbs did not go straight home. He stayed in London, patented a new lock, and founded Hobbs & Co. in the banking district — his own firm, in the city he had arrived to embarrass. The original challenge lock sits today in the Science Museum in London, keyhole still visible. Sixty-seven years of silence, it turned out, had never been proof.
Sources
- Bramah lock — Wikipedia — mechanism, 18-slider design, 470 million permutations, the challenge lock, Science Museum location.
- National Insecurity — Cabinet Magazine — Hobbs at the Great Exhibition, Chubb picking at the Crystal Palace, newspaper controversy, arbitration, aftermath.
- Alfred Charles Hobbs and the Great Lock Controversy — History of Safes — Bank of England response, Hobbs’s London career.