Smedley's was described, under the sub-heading "Smedley's Home of Health" in "Truth"^[1], a supplement published for the hydro in 1926, as follows:

"Overlooking the valley of the Derwent from an altitude of 500 feet above sea-level, Smedley's famous "Hydro", consisting of a long line of handsome buildings with spacious grounds and many fine trees, makes an interesting feature on the hillside known as Matlock Bank. Its windows and balconies, and the terraces that range the south-western slopes of the hill, command expansive views of picturesquely undulating Derbyshire countryside, bounded by High Tor, Masson, and the castle-capped Riber Hills. Pine-clad peaks tower protectingly above the house to the north-east, and afford ample shelter from the more rigorous winds. Yet, by reason of all its eminence and aspect, Smedley's gets the full benefit of the south and west, and also enjoys a maximum of sunshine. The air is dry and rather bracing, and the water, of which a plentiful supply is derived from the high and open moorland reaches which stretch mile after mile to the northwards, is of exceptional softness and purity^[1]".

The hydro clearly used this image in its publicity material and as a postcard for many years. For example, if you look at the right hand end of the building, you will notice that the chimney of the boiler house is not shown - it was erected in 1894 and over thirty years before the picture was published in "Truth".

By 1926 Smedley's could accommodate 400 people. "It is spacious and elegant in design, well-lighted, and well-ventilated ; and in cold weather, a carefully controlled central-heating installation keeps all bedrooms and corridors at an even temperature with the public rooms^[1]". "Truth" claimed that life at Smedley's need never be dull. There were electric bathrooms, with special rooms "reserved for Galvanic, Faradale, high frequency, ionisation, diathermy and ultra violet treatment". Radiant heat baths had been used for some years and a "new full Downing bath of the latest pattern" had just been added^[1]. There were also Turkish and Russian baths.

Other treatments available at Smedley's were:
Rain or needle baths.
Spray baths, general and local.
Sponge or hip baths.
Shallow or long baths.
Sitz baths, hot, cold and flowing, etc.
Foot baths, the same.
Head, eye, ear, and nose baths.
Ascending douches and spray baths.
Douches, vertical, horizontal, hot and cold.
Rectal and vaginal douches.
Douches, local and spinal, hot and cold, successive and alternate.
The Aix douches and Vichy douche.
Wave baths.
Steam boxes and vapour baths, both for general and local purposes.
Domestic plunge baths in private suites.
Swimming baths^[2].

References:

^[1] "Truth" Special Publicity Supplement - No.77. The Quest of Health. 25th Aug., 1926. Printed for the Proprietors by St. Clement's Press, Ltd., Portugal Street, Kingsway, W.C.2 and Published by the Advertising Department of the Truth Publishing Co. Ltd at 10 Cartaret Street, Westminster, S.W.1 (with thanks to Jane Leslie).

^[2] Peach, Lawrence du Garde (1954) "John Smedley of Matlock and his Hydro", Bemrose Publicity Co.: Derby & London. Also see: Smedley's brochure of about 1925.