Long before Gott, the mill had a quieter life. A clothier named Richard Booth leased 'Armley Millnes' from Henry Saville in the middle of the sixteenth century, and by 1707 a single building housed two waterwheels, four fulling stocks, and a corn grinder. Fulling was the dirty heart of woollen finishing - hammers pounded soaked cloth in vats of water, urine, and Fuller's earth, the ammonia helping to felt the fibres into something durable. Householders along the lane saved their urine in jars and sold it to the mill. By 1788 five waterwheels powered eighteen stocks, and Colonel Thomas Lloyd, a Leeds cloth merchant, bought the operation and built it into the largest woollen mill on Earth. He never lived there himself. The Burrows brothers, who ran the place day-to-day, built semi-detached cottages on the far bank of the canal so they could watch the wheels turn from their windows.

After the 1804 fire, Gott rebuilt to fireproof principles pioneered just years earlier. The new mill is L-shaped on sloping ground, varying between two and four storeys, twenty-three bays of ashlar stone running north to south above the millrace. Inside, slender cast-iron columns carry shallow brick arches instead of timber floors. The six finely detailed arches at water level, with their wrought-iron grills, are still visible from the riverbank. The wheels Wellington and Blucher were suspension wheels with rim-gearing - a technique developed by the engineer Thomas Hewes - rated at 70 horsepower between them. A beam engine joined them in 1855, and by the 1860s steam had quietly replaced moving water. The wheels themselves were dismantled in 1885, though photographs survive of them turning in the dark.

Walk along the canal towpath toward the canal-side wharf called Botany Bay Yard, and you find a piece of trade history hiding in plain sight. This was the first place in England where wool shipped from Botany Bay - the new colony at Sydney, half a world away - was unloaded. A wharf shed still stands here in ruins, and beside it, sunk into the canal mud, sits what looks like the remains of a wooden barge. The mill at the end of the wharf was Gott's. Australian fleeces travelled fourteen thousand miles by sail, were dragged up the canal by horse, and were combed and woven into cloth that left Leeds again for markets across the British Empire. The world of the mill was small and very large at once.

By 1907 part of the mill had been let to tenants under a 'room and power' agreement - small clothing manufacturers renting floor space and shaft drive from a single mill engine. The firm Bentley and Tempest worked the looms here for decades; their accident book, still in the museum's collection, records the small daily violence of textile work. The mill closed for commerce in 1969. Leeds City Council took over the buildings, and in 1982 reopened them as a museum of industrial heritage. The Grade II* listed structure now houses textile machinery, railway equipment, locomotives, and the printing presses, sewing machines, and engines that powered Victorian Leeds. The wooden corn-mill wheel still stands inside, in need of repair but unmistakeably there - the older bones of the place, visible if you know where to look.

Leeds in the eighteenth and nineteenth centuries was the city of a thousand trades, and Armley Mills tells the story from the bottom up. The collections cover wool, worsted, ready-made clothing, locomotives, printing, and cinema - the industries that paid for the Town Hall and the arcades. Among the holdings is the world's oldest surviving model locomotive, a piece of engineering history hiding in a Yorkshire suburb. The mill flooded in 2015 when the Aire burst its banks - a reminder that the same river that powered the looms can still rearrange the place when it wants to. The museum reopened, the looms came back online for demonstration, and the wheels of Wellington and Blucher, now phantoms, still tug at the imagination of anyone walking the towpath.