Once I saw the most remarkable rainbow of any I can remember. It was not double – I have seen double rainbows, and they are certainly a wonderful sight. No, this was a single, ordinary rainbow, if anything as wonderful as a rainbow can be called ordinary. It was complete, bold and beautiful in colour, spread across a broad, dramatic peakland sky, extending over the far tree-lined drystone wall of a sheep meadow which in turn I viewed over another drystone wall.

The bow shone against a backdrop of grey and white clouds amply interspersed with blue sky. The sheep field shone green in the sun and two sheep wandered along the far wall. A fine cloud-mist cooled my face.

I was walking with Kate, a small west highland white terrier, and was brought to a halt by the spectacle. Kate, with the poor colour-sense of all dogs, ignored it and nosed along in the long grass getting slowly covered in goose-grass burrs while I stood transfixed. I paid for it later when I had to pick them off.

It is hard to describe my feelings as I stood for over ten minutes watching the changing moods of the sky and fields. At times the entire bow was seen against a backdrop of clouds except where its earthbound ends dipped to the trees and wall. Occasionally it stood out in places against blue sky which shone through it although the spectral bands could still be clearly seen. Sometimes the field below darkened with cloud shadows and yet the rainbow persisted above. There were no great drops of rain, just the fine cloud-mist against my face from a large irregular cloud that was passing over me. Any moment I expected the greater flurry of rain that often comes at the tail of a cloud, but it did not come. Only the fine refreshing cloud-damp blowing through my hair and lightly in my face.

Behind me a low morning sun gleamed through the silver-gold lining of a grey cloud, that seemed almost stationary compared to the wracks passing overhead. In front, the tail of cloud moved, oh so slowly, toward me. The rainbow was fixed, bright and constant. The sheep ambled to and fro then moving off to my left passed through the rainbow’s end by the wall.

Suddenly a thin cloud crossed the sun and the bow dimmed only to brighten again as the sun penetrated more strongly. Steadily the tail of the cloud moved toward me. The blue sky grew in its wake. The wind tossed leaves through the air and ripples through the grass. Kate lay down, thought better of it and nosed off after some fascinating scent. The clear sky grew until the whole bow was spread out against the blue vault of the heavens – something I had never seen before. Then, very slowly over several minutes, rain and bow faded together leaving a brilliant morning sky.

I pondered that a rainbow can fade in two ways: because the sun is dimmed or because the rain clears, and that I could be struck by beauty while my colour-blind companion saw nothing at all.

I stayed a few moments looking at the scene, then turned to go. To my amazement the rainbow colours returned in a flash. There was no rain, just the sun shining in the drops in my hair and lashes. I carried the rainbow with me.