Arthur Conan Doyle,
The Horror of the Heights
(1913)
“ There was a second--opal- coloured and fleecy--at a great height above my head, a white, unbroken ceiling above, and a dark, unbroken floor below, with the monoplane labouring upwards upon a vast spiral between them. It is deadly lonely in these cloud-spaces. Once a great flight of some small water-birds went past me, flying very fast to the westwards. The quick whir of their wings and their musical cry were cheery to my ear. I fancy that they were teal, but I am a wretched zoologist. Now that we humans have become birds we must really learn to know our brethren by sight. ”
