Power Plugs of the World
A Brief
History of
the Wall Socket
Before the plates: a hundred-and-twenty-year argument about how to deliver electricity through a wall, conducted simultaneously in Connecticut, Berlin, London, and Geneva, and never quite resolved.
Edison · New York
The Screw Lampholder
Edison's E26/E27 screw socket distributes electricity through a hole in the wall — but only to lightbulbs. The wall socket as we know it does not yet exist; appliances are wired in.
Smith · England
The Two-Pin Adapter
T. T. Smith patents a screw-in adapter that converts a lightbulb socket into a two-pin outlet. For two decades, this is how Britons plug in their irons.
Hubbell · Connecticut · Patent 774,251
The Separable Attachment Plug
Harvey Hubbell patents a plug that detaches from its socket. The single most consequential idea in the field: an appliance is no longer wired to the wall; it visits.
Hubbell → NEMA
Parallel Flat Blades
The round pins flatten into blades. The result, codified later as NEMA 1-15, becomes the ancestor of Plate 01 · Type A/B.
Bayerische Elektrizitäts-Werke · Munich
Schuko (Schutzkontakt)
Albert Büttner patents the round, recessed plug with side-grounding clips — Germany's answer to safety. Becomes Plate 05 · Type F.
British Standards · London
BS 372 — Round-Pin Three
The first British attempt at a unified plug. Three round pins in a triangle — its descendant survives in India as Plate 03 · Type D.
Britain · Post-War Reconstruction
BS 1363 — The Fused Plug
Britain's answer to its bombed-out wiring: a hulking, fused, three-rectangular-pin plug rated to 13 amps. Plate 06 · Type G — still the safest plug ever made.
Switzerland · SEV
SEV 1011
The Swiss commit to a hexagonal recess and three offset round pins — incompatible with everything around them, by design. Plate 09 · Type J.
CEE · Continental Europe
The Europlug — CEE 7/16
A diplomatic compromise: a flat, ungrounded, low-current plug that fits almost every European socket — French, German, Italian, Spanish, Swiss. Plate 02 · Type C.
IEC · Geneva
IEC 60906-1 — A World Plug
The IEC proposes a single global standard. Only Brazil adopts it (as Plate 13 · Type N, 2007), and the world remains, by a large margin, fifteen.
The Present · This Volume
Fifteen Plates, One Atlas
A hundred-and-twenty-two years after Hubbell, fifteen distinct domestic plug types remain in service. They are catalogued in the plates that follow.
& Drift
Why the world never agreed
Every plug standard was set nationally, decades before international travel was common. By the time anyone proposed a unified system, hundreds of millions of sockets had already been poured into walls. Replacing them — re-wiring entire countries — has always been more expensive than carrying an adapter.
Britain's BS 1363 is the outlier: it was rolled out after wartime destruction made re-wiring a national project. Most countries never got the same chance.
The voltage drift
Plug shapes are only half the story. The transatlantic split between 120 V at 60 Hz (the Edison world) and 230 V at 50 Hz (the European world) was settled by 1900 and has never moved.
Mains Drift1900 → 2026
Dispatch
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Send us a plug from where you are.
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Send us a plug from where you are.
Spotted a curious socket on the road? Snap a photo, tell us where you took it, and we'll catalog it on Instagram. The best dispatches are reposted with credit and printed in a future "Field Reports" appendix to this atlas.