Before 1802, clouds had no agreed names. People spoke of mackerel skies and mares' tails, and a cloud was whatever you said it was. Then a London pharmacist and Quaker named Luke Howard, who loved to watch the sky, proposed a system that made sense of them.
Howard was born in 1772 and ran a chemical business, but he spent his spare hours recording the weather. In December 1802 he read a paper called On the Modification of Clouds to a small scientific club in London, the Askesian Society, and it was published the following year. He argued that clouds, which looked wild and random, fell into a handful of basic forms that change from one to another in a regular way.
He chose Latin for his names because it was the common language of scholars across Europe. Cirrus means a curl or lock of hair, for the high, wispy kind. Cumulus is a heap. Stratus is a layer or sheet. Nimbus is a rain cloud. He also described blends, such as cirrostratus and cumulonimbus, and those compound names are still in use.
Howard lived to be ninety-one, and he became something of a celebrity in the world of science. His scheme has been adjusted and extended, but its heart is intact. Every time someone says that a cumulus is passing or a nimbus is approaching, they are speaking his language.
