Standing in front of a real tide machine changes you. Photographs flatten them; in person you grasp the mass, the smell of oil and oak, the absurd fineness of the pinions. This guide lists every surviving machine I have personally verified through museum records and correspondence — always confirm display status before travelling, because galleries rotate.
London: the Science Museum
The spiritual home. The collections hold Kelvin-era predictors including the South Kensington demonstration model descended from the 1872 prototype. When displayed, look for the slotted crank pins (see the setup ritual) and the wire cascade to the pen. Check the museum’s online collection record before visiting — large instruments rotate in and out of storage.
Washington: the American giants
The US Coast Survey’s machines, including elements of the record-holding Machine No. 2, survive in federal and Smithsonian-linked custody. These are the biggest brasses anywhere — 37 constituents of ambition. Access varies between open display and research-store visits; write ahead.
Munich and Hamburg: the German school
The Deutsches Museum (Munich) and Hamburg collections preserve Gezeitenrechenmaschinen from the tradition I profile in Germany’s Forgotten Competitors. German machines reward close looking: shortened symmetric wire runs and cabinetry built like astronomical clocks. In Hamburg, ask about the shallow-water pinion banks — the fast little wheels that tamed estuarine tides.
Bidston and Liverpool: the rigorous years
Legacy instruments and records of Bidston Observatory survive through Liverpool-area museums and archives. The display is smaller than London’s but intellectually the richest: Doodson’s analysis sheets beside the machines that embodied them. Pair a visit with my harmonic analysis explainer for full effect.
What to look at on any machine
- The mesh points — smallest pinions first (why they matter).
- The crank pins — slid out for big constituents, home for small ones.
- The wire cascade — trace one wire from crank to pen (how it adds).
- The nameplate — maker, date, office. Photograph it; nameplates settle more historical arguments than textbooks.
- The paper roll (if fitted) — the machine’s handwriting; learn to read it with my roll guide.
What visitors ask
Do any still run? A few are turned by hand on special demonstration days — the closest you will come to 1910. Demonstration schedules are irregular; ask the museum directly.
Can I photograph them? Most displays allow non-flash photography; research stores vary. Always ask, and never touch brass without invitation — skin acids etch.
How did this list get verified? Collection databases, published catalogues, and direct correspondence. If you find an error or a newly displayed machine, tell me — corrections are published with credit.
Plan the trip
Two days, three cities, five machines — that is my recommended first itinerary: London for the Kelvin line, Washington or Munich for the giants, Liverpool for the rigorous school. Check display status the week before (galleries rotate), bring the five-point looking list from this article, and photograph every nameplate. Then come home and decode your photos with the glossary — the labels will read like letters from the builders. If you find a machine I haven’t listed, the contact page is open and credit is published.