The redecorated hall was intended to evoke features of 'shock' and 'amazement' in the viewers' minds; the room from where views of the waterfall were taken was lined with mirrors which made the spectator imagine that the water was appearing from all angles.
The guide operated a device that withdrew the painting into the wall, providing access to another room - a hall of mirrors - giving the illusion of water pouring all around reflecting the river cascading outside.
In 1803 Dorothy Wordsworth wrote "The waterfall, which we came to see, warned us by a loud roaring that we might expect it; we first, however, conducted into a small compartment, where the gardener desired us to look at a painting of the figure of Ossian, which, while he was telling us the story of the young artist who performed the work, disappeared, parting in the middle, flying asunder as if by the touch of magic, and lo!
we are at the entrance of a splendid room, which was almost dizzy and alive with waterfalls, that tumbled in all directions - the great cascade, which was opposite to the window that faced us, being reflected in innumerable mirrors upon the ceiling and against the walls".
In 1943 the 8th Duchess of Atholl donated it and 33 acres (13.3ha) of, by then, coniferous woodland along the banks of the River Braan to the National Trust for Scotland in accordance with the wishes of the late Duke.