Alone among the great free-reed makers, Wheatstone & Co. of London kept its factory books — and alone among those books, they survive. Seventeen ledgers, roughly 2,300 pages, covering the firm’s production from 1834 to 1974, were digitised by the Horniman Museum and are free to read. That is why a Wheatstone concertina can be dated the way no accordion ever can: from the maker’s own handwriting.
What the books hold
A production entry is a small biography: the serial number, the date it was entered, the model and the purchaser — sometimes the very day an instrument left the workshop. About sixty thousand Wheatstones were ever made; the ledgers capture the overwhelming majority of them in blocks. The digitised books split into two ages: the Wayne archives (1834–1891) and the Dickinson production ledgers (1910–1974).
How the buttons of the archive work
We turned the volume indexes into dating ranges. The earliest book — the “First Number Book” — carries serials 1–1500 through 1849. The production ledger C1054 covers 18,061–21,353 through 1891; the Dickinson volumes then run 25,000–29,749 (1910–1923), 29,750–34,449 (1923–1937) and 34,450–37,083 (1937–1974). Each of these is a ledger in the strict sense: the years come from the factory pages themselves, which is why entries from this archive carry the highest confidence label we have.
Two things the ledgers teach you
The books have honest holes. Between 1839 and 1870 only sales ledgers survive — they record the day an instrument changed hands, not the day it was built, so we deliberately do not date from them. And two true gaps remain: roughly 21,354–24,999 (about 1891–1910) and 37,084–55,491. If your number falls there, the honest answer is “the ledgers are silent” — and for the early Victorian stretch a published community table fills in finer boundaries.
Wheatstone ran two series at once. After 1938 an Anglo concertina’s number and an English or Duet’s number come from different books: the English/Duet run continued in the 3xxxx block while Anglos began a parallel 5xxxx block (the surviving Anglo ledger covers 55,492–59,498, 1953–1974). Before trusting a lookup, identify the system — English, Anglo or Duet. Our Wheatstone lookup asks for exactly that.
What about other concertinas?
Lachenal — the great mass producer — burned differently: its records were destroyed when the firm passed to Wheatstone in 1936. Its dates are reconstructed from manufacturers’ formulas (accurate to roughly a decade, and clearly labelled as estimates) and from dated museum instruments. Crabb hid the year inside its ID numbers for a brief window (1937–1939), and Jeffries never numbered at all — it is dated by the address on its label. The brand directory shows which route each maker takes.