When the author Nan Shepherd was walking the Cairngorms in the 1940s, she once dedicated an entire day to studying the ice patterns in the burns, writing about them in her now-iconic book The Living Mountain. A quote from it is on the Royal Bank of Scotland £5 note: ‘But the struggle between frost and the force in running water is not quickly over. The battle fluctuates, and at the point of fluctuation between the motion in water and the immobility of frost, strange and beautiful forms are evolved.’
I am writing my own Cairngorms book in response to her work, so following her example, I take a slow winter day in the hills watching ice and water. My trail leads up Allt Mor, ‘the big stream’, that runs from the ski slopes on Cairngorm mountain down into the Glenmore forest. A stretch of water under a bridge looks fluid, until a certain angle reveals an intricate cross-hatching, like the frost patterns on a window. The whole decorated surface is thin as film and blends without border into the flow.
Leaves captured in frozen puddles become works of art.
Higher up, more ice appears. It forms a shiny skin over rocks rising from the stream, tight as varnish. Climbers call it verglas or glaze ice and curse it, offering the counter-intuitive advice to ford streams on stones just below the running water, as they will not be icy. Often, verglas sits like a cap on a rock, with its bottom edge fringed with baubles where the running water has splashed and frozen. When the glaze has thawed a little, water slides under it in runnels like shape-shifting tadpoles.
Long crystals hang in pendulous curtains from the mossy boulders, grasses and heathers that overhang the burn. They bubble out in fanciful shapes, thickly clouded or crystal clear, straight and smooth or knobbled.
Higher still, there is snow. Heaped in bridges and banks, it sometimes morphs to ice on its way to the water, forming glassy towers and spires worthy of the wildest science fiction.
On a rock loosely furred with ice, the water flow is caught and released in a rhythmic pulse that makes it look like a living creature, a beating heart of stone on the living mountain.
As Shepherd said, ‘There is no end to the lovely things that frost and the running of water can create between them.’
A version of this article first appeared in the Guardian Country Diary.