This article appeared in the TES Teacher supplement on 17 January 2003
‘Water with Altitude: Luke Howard and the Naming of Clouds’
On a cold December evening in 1802, the forty or so members of an amateur science club made their way down a steep flight of stairs and into a cavernous laboratory in London, where a nervous young man was preparing himself to deliver that evening’s lecture. The usual discomforts of public speaking would have been worse for a Quaker, and worse still for one as self-doubting and preoccupied as the thirty-year-old chemist Luke Howard. Even the title of his lecture, ‘On the Modifications of Clouds’, seemed modest and understated compared with the titles of some of the other talks that had been delivered to the science club over the course of that winter: ‘On the Explosivity of Gunpowder’, for example, or ‘On the Surprising Powers of the Divining Rod’. But anyone who doubted the potential significance of Luke Howard’s lecture on that particular winter night would have been in for a surprise. For what the audience was about to witness remains one of the most extraordinary episodes in the history of British science: the naming of clouds by an unknown young amateur meteorologist who, by the end of the evening, was being heartily congratulated by the members of his audience, but whose fame, by the end of the following year, had spread throughout the scientific world.
Luke Howard was not the first to have attempted to understand atmospheric clouds. Since antiquity, clouds have offered a challenge to their observers to provide a satisfactory account of their cause and their behaviour, while their fleetingness has also supplied a powerful image of the changeability and transience of life. “The patron goddesses of idle men”, as the Athenian playwright Aristophanes described them, clouds have long been a subject close to the hearts of scientists and daydreamers alike. But no-one, not even in antiquity, had ever succeeded in naming them. Many Greek and Roman scientific thinkers, such as Aristotle, Seneca and Lucretius, offered hopeful and often ingenious explanations of cloud formation and structure, but none of them ever hazarded a taxonomy, or a systematic method of classification.
The compilers of the Norse myths, however, came close to a kind of mythical taxonomy, devising a sequence of cloud types that took their definition from the altitude at which they were found: the high wispy clouds which we now call cirrus, for example, were spun by Frigg, the wife of Odin, on her wheel and distaff in her celestial home in the Palace of Mists. The lower, cumulus clouds, meanwhile, were flung upwards during the summer months by the dying frost giant Ymir. And the ghastly citadel of Hel was shrouded in a permanent brooding sheet of the low-lying cloud that we now call stratocumulus.
Myths aside, it wasn’t until the seventeenth century, and the coming of the Scientific Revolution, that natural philosophers (as scientists in Europe then called themselves) began to emphasise the importance of classifying natural objects into groups and categories in order to establish both the connections and the differences between them. In the early eighteenth century the Swedish botanist Carl von Linné (who was known to the Latinizing world as Linneaus) introduced the system of binomial nomenclature to natural history, in which every identifiable kind of organism could be designated by a pair of Latin names. The first name denoted the genus to which the organism belonged, while the second denoted its species. So Acer japonicum, for example, referred to the Japanese maple, while Canis familiaris referred to the domestic dog. The Linnean system of naming allowed connections and differences to be recorded across a wide spectrum of natural history, and it proved hugely influential, inaugurating the great age of scientific naming and fixing, during which everything, from the greatest of the mammals to the smallest of the microbes, was classified for study or stuffing.
Luke Howard, like most scientifically-minded men and women of the age, was familiar with the Linnean system of naming, as well as with Latin in general. He had been sent to a Quaker boarding school in Oxfordshire where Latin formed the heart of the curriculum. It was there, according to Howard, that he first began to notice the shapes of the clouds, as he stared out of the schoolroom windows at the sky. “I settled in my mind one remarkable configuration of the Clouds in a full sky”, he recalled later, “because it was of rare occurrence,” and he kept notebooks of his observations of the skies. It was this early combination of schoolroom Latin with an innate curiosity for natural forms that would lead on to his achievement in 1802, when he gave the clouds the names by which they would be known for all time.
But while Luke Howard’s audience at the science club lecture would have been familiar with the Linnean system of classification, they would have known very little about clouds. Meteorology was one of the sciences’ slower developers, and even by the early nineteenth century it had advanced little beyond the wisdom of ancient proverbs such as “red sky at night: shepherd’s delight; red sky at morning: shepherds take warning.” Part of the problem with meteorology, of course, was the intangibility of many of the phenomena which it studied. Unlike its neighbouring disciplines such as botany or geology, it was difficult to do the kind of fieldwork in meteorology which would build up a collection of samples that could be studied at leisure, and then named and arranged into a revealing system. The language of classification was the backbone of scientific study in Howard’s time, much more so than it is today, with the cabinet of samples acting as its primary tool. Meteorologists thus suffered a distinct disadvantage, being unable actually to collect study samples of winds or clouds or rainbows. All they could collect were columns of statistics of rainfall, wind-speed, temperature and pressure. And as Howard pointed out at the beginning of his lecture in 1802, “the philosopher who attends only to his instruments may be said only to examine the pulse of the atmosphere.” What was needed, in his view, was a foundation of classification upon which meteorology could then be built into a recognisably modern science. And clouds, he felt sure, were the key to the problem.
Clouds, according to Howard, are the visible signs of the otherwise invisible processes of the atmosphere. They write a kind of journal upon the sky which, were we to take the trouble to learn to read it, would allow us to understand the patterns of weather and climate much better than before. Howard had devoted much of his time to learning to read this language of the sky, and the results of his labours were presented in his brilliant lecture of December 1802 in which he laid out the scientific classification and nomenclature of clouds.
What led to the success of Howard’s classification of clouds was his simple but penetrating insight that clouds have many individual shapes but very few basic forms. In fact, he claimed, all clouds belong to one of only three main families, to which he gave the names cirrus, cumulus and stratus. Every kind of cloud is either a modification of or a transition between these three major families of cloud. Following the Linnean example, Howard took his names from already existing Latin words: cirrus, meaning fibre or hair; cumulus, meaning heap or pile; and stratus, meaning layer or sheet. [NB: pics of these?] Other, intermediate cloud forms were then named by Howard according to their relation to these principal types. So a high, wispy cirrus cloud that descended and spread into a sheet was named as cirrostratus, while groups of fluffy cumulus clouds that joined up and spread were named as stratocumulus. Howard identified seven cloud types in his original lecture, which have since been expanded to ten: cirrus, cirrocumulus, cirrostratus, altocumulus, altostratus, nimbostratus, stratocumulus, stratus, cumulus and cumulonimbus.
What was so ingenious about this apparently simple system was that it allowed for the changeability of clouds. Howard recognised the fact that clouds continually merge, one into another, they rise, fall and spread throughout the atmosphere and across the sky, rarely maintaining the same shape for more than a few minutes at a time. Yet Howard’s classification allowed for all this restless movement and change; it allowed the clouds to move and modify and exercise their elemental freedom. This was something new in science, as many of Luke Howard’s contemporaries realised, and when it was published, in 1803, his classification of clouds was to have a widespread impact, not just upon the development of atmospheric science, but upon early nineteenth-century European culture as a whole.
Johann Wolfgang von Goethe, for example, the greatest intellectual icon of his age, wrote a series of poems in praise of Howard’s clouds, in which he eulogised Howard for his “clearer mind”, and which ended with the memorable lines:
As clouds ascend, are folded, scatter, fall,
Let the world think of thee who taught it all.
Percy Bysshe Shelley, too, wrote a poem, “The Cloud”, in which each of Howard’s cloud types was characterised in turn. But perhaps the most impressive reaction to Luke Howard’s naming of clouds was in the work of the painter John Constable, who spent two entire summers on Hampstead Heath, painting clouds from the life in an effort to understand them meteorologically as well as visually. He owned a copy of Luke Howard’s published lecture, which he annotated carefully, and he also wrote detailed weather notes on the back of each of his sketches. There are over a hundred of these oil sketches still in existence, and they are now among the most revered of all John Constable’s works.
Howard himself, however, did not enjoy the scientific celebrity that his cloud classification soon brought him. As an orthodox Quaker he viewed worldly acclaim with something approaching trepidation, and although he continued to pursue his meteorological interests, going on to publish a number of books on the subject, he kept himself at a far remove from the life of public science that could otherwise have been his. “I am a man of domestic habits”, as he wrote in a memoir later in his life, “and very happy in my family and a few friends, whose company I quit with reluctance to join other circles.”
So while Luke Howard’s names for the clouds have continued to be remembered and used all over the world, his own name has largely been forgotten, which is exactly what he would have wanted. He died in 1864, at the age of 91, and was buried in an unmarked grave.
But on a cold April morning in 2002, forty or so members of an invited audience gathered on a London pavement to witness the unveiling of an English Heritage blue plaque in honour of the memory of Howard. Michael Fish, the BBC weatherman, presided over the event, which was organised and hosted by the Met Office. The wording of the plaque, which is fixed high on the wall of 7 Bruce Grove, Tottenham, the house in which Luke Howard spent the last twelve years of his life, is beautifully succinct:
Namer of Clouds
Lived and Died Here
Yet Luke Howard’s true memorial remains the names that he bestowed upon the clouds exactly two hundred years ago, and which are spoken every day around the world. And in naming the clouds, in giving language to things that had hitherto been nameless and unknowable, Luke Howard transformed for ever the relationship between the world and its overarching sky.