In the late nineteenth century, it was extensively redeveloped by the "Harrogate Hydropathic Company" as a fashionable spa hotel and included Turkish baths.

The steam engine was re-activated to drive the laundry by Jack Gill of John Redfearn's garage at the hotel in the 1950s until electric motors took over.

In 1939 the hotel was requisitioned at 48 hours' notice by the Ministry of Aircraft Production and cables were laid to a new telephone exchange in the Library Restaurant.

The "Bath Chair" image of Victorian spa towns was now unfashionable and the Hydro was renamed "The Old Swan Hotel" "famous since 1700".

She was missing for a total of eleven days, during which the police conducted a major manhunt, and there was speculation that she had committed suicide.