Luke Howard:
The Man Who Named The Clouds

Cirrus, stratus, cumulus. We take these terms to describe the clouds above us pretty much for granted these days, often assuming they are names of ancient origin. While great age can be ascribed to their Latin roots, the specific terms for various basic cloud forms are not yet two centuries old and were only accepted as the international standards during the Twentieth Century.

The man whom we must credit with developing the basis for our cloud classification system was Luke Howard (1772-1864), an English manufacturing chemist and pharmacist. Like many who observed and studied the workings of the atmosphere at that time, Howard was an amateur meteorologist. Despite that fact he produced several landmark works including On the Modification of Clouds, The Climate of London, and Seven Lectures on Meteorology, the first textbook on weather.

I first became familiar with the name of Luke Howard during my studies of urban climatology and air pollution. Only years later did I learn that he had also originated the cloud classification system I used daily. [Despite his many achievements, Luke Howard rarely rates more than a sentence or two in most weather books. I am indebted to Dr John Day for much of the information presented on the man himself in this essay.]

Early Years

Luke Howard was born 28 November 1772 in London, England, the first-born of Elizabeth and Robert Howard. Robert Howard was a successful businessman and devote Quaker and these allowed him to send young Luke to a large Quaker grammar school located at Burford, a community near Oxford, as soon as he reached school age.

While Howard was never trained as a scientist, he had a love for nature and the weather, particularly the clouds, from an early age. John Day has written that Howard's fascination with clouds was kindled by the incredible skies of 1783. Between May and August of that year, the Northern Hemisphere sky was laden with a "Great Fogg", a haze composed of dust and ash from violent volcanic eruptions in Iceland (Eldeyjar) and Japan (Asama Yama). The unusual skies drew the attention of most of the diarists of the day and many novelists used them as backdrops for their stories. Added to the spectacle of the persistent volcanic ash pall was a fiery meteor which flashed across western European skies during the early evening of 18 August, a sight observed by the eleven year-old Luke.

These events appear to have captured Howard's interest and riveted his attention to the skies. He became a devoted observer of the atmosphere for the rest of his life, augmenting his visual observations with readings from barometer and thermometer. For over 30 years of his life, Luke Howard maintained a record of accurate meteorological observations.

Naming The Clouds

Prior to the beginning of the Nineteenth Century, most weather observers believed that clouds were too transient, too changeable, too short-lived, to be classified or even analyzed. With few exceptions, no cloud types were even named; they were just described by their colour and form as each individual saw them: dark, white, grey, black, mare's tails, mackerel skies, wooly fleece, towers and castles, rocks and oxes-eyes. Clouds were used in a few instances as forecast tools in weather proverbs, but mostly by their state of darkness or colour:

"Red sky in morning, sailor take warning."

"Mackerel skies and mare's tails, make lofty ships carry low sails."

Then within a year, two cloud classification schemes were independently developed by Jean Baptiste Lamarck of France and Luke Howard of England. Likely both schemes were inspired by the work of the great Swedish taxonomist Carl von Linne, know to us as Linneaus. Linneaus' systematic classification scheme for all life forms was one of the most significant scientific milestones of the Eighteenth Century and was adopted by scientists and naturalists around the world. We know that Linneaus' work had a profound influence on Howard, resulting in a paper on pollens presented to the Linnean Society of London in 1800.

Lamarck was the first to present his cloud classification, publishing it in 1802 in the third volume of his Annuaire Méteorologique in a paper entitled "On Cloud Forms." Lamarck realized the importance of clarity in observing meteorological phenomena:

"It is not in the least amiss for those who are involved in meteorological research to give some attention to the form of clouds; for, besides the individual and accidental forms of each cloud, it is clear that clouds have certain general forms which are not all dependent on chance but on a state of affairs which it would be useful to recognize and determine."

He initially proposed five main types of clouds "related to general causes which are easily ascertained." They were:

Hazy clouds (en forme de voile)
Massed clouds (attroupés)
Dappled clouds (pommelés)
Broom-like clouds (en balayeurs)
Grouped clouds (groupés).

Three years later, Lamarck devised a more detailed classification scheme which comprised twelve forms. Unfortunately his classification system did not make an impression on the scientists and naturalists of the day, not even his countrymen and does not seem to have been used by anyone, except himself. Two possible reasons were given, in to the "Preface" of the International Cloud Atlas (World Meteorological Organization, 1939): ...due to his choice of somewhat peculiar French names which would not readily be adopted in other countries, or perhaps the paper was discredited through appearing in the same publication (Annuaire Méteorologique) as forecasts based on astrological data."

During the winter 1802-03, (records do not give an exact date although John Day believes it may have been in December 1802), Luke Howard presented a paper to the Askesian Society, of which he was a founding member, entitled "On the Modification of Clouds." (Day remarks that the word modification in the title would in today's English be replaced by classification.)

In that paper, Howard proposed that one could identify several simple categories within the complexity of cloud forms. The great leap that Howard took was to provide his descriptive categories with Latin names (as Linneaus had done with the plant and animal kingdoms), the language of scholarship, thus transcending national and language borders in its usage. Unlike Lamarck's names, these were understandable to all European-derived cultures (and in non-European lands where the Catholic Church had made inroads, bringing Latin to the local scholars). And it did not hinder the system's acceptance that is was both very simple and nearly all-encompassing.

Howard believed all clouds belonged to three distinct groups:

	Cumulus (Latin for heap)	"Convex or conical heaps, increasing upward from a horizontal base -- Wool bag clouds."
	Stratus (Latin for layer)	"A widely extended horizontal sheet, increasing from below."
	Cirrus (Latin for curl of hair)	"Parallel, flexuous fibres extensible by increase in any or all directions."

To denote "a cloud in the act of condensation into rain, hail or snow," he added a fourth category:

Nimbus
(Latin for rain)

"A rain cloud -- a cloud or systems of clouds from which rain is falling."

According to Howard: "While any of the clouds, except the nimbus, retain their primitive forms, no rain can take place; and it is by observing the changes and transitions of cloud form that weather may be predicted."

Clouds could also alter their forms, thus, Howard reasoned, when cumulus clouds bunched together so that they crowded the sky, they became:
Cumulo-stratus:
"The cirro-stratus blended with the cumulus, and either appearing intermixed with the heaps of the latter, or super-adding a widespread structure to its base."

Similarly, he defined other intermediate categories of transformation:

Cirro-cumulus:
"Small, well defined, roundish masses increasing from below." and
Cirro-stratus:
"Horizontal or slightly inclined masses, attenuated towards a part or the whole of their circumference, bent downward or undulated, separate, or in groups, or consisting of small clouds having these characters."

He would later write of the classification system:

"The names ... were intended as arbitrary terms for the structure of clouds, and the meaning of each was carefully fixed by a definition ... (Local terms) take away from the nomenclature its present advantage of constituting ... an universal language, by means of which the intelligent of every country may convey to each other their ideas without the necessity of translation. And the more this facility of communication can be increased, by our adopting by consent uniform modes, terms, and measures for our observations, the sooner we shall arrive at a knowledge of the phenomena of the atmosphere in all parts of the globe, and carry the science to some degree of perfection."

The Climate of London, Volume II (1820)

Howard's work made a big impression on those interested in the sky, particularly after his papers were reprinted in Thomas Forster's successful Researches About Atmospheric Phaenomenae in 1813. The classification system quickly gained wide acceptance both in Britain and other countries. Among its biggest supporters was the German poet, philosopher and scientist Johann Wolfgang von Goethe. Goethe used the Howard classification in his weather journals and eventually dedicated four poems to Howard and his Clouds.

Goethe wrote:

[Howard] "was the first to hold fast conceptually the airy and always changing form of clouds, to limit and fasten down the indefinite, the intangible and unattainable and give them appropriate names."

Howard's work on clouds also appears to have influenced many Romantic Era painters, notably masters Joseph M.W. Turner, and John Constable of England and Caspar David Friedrich (through Goethe) in Germany. They used Howard's descriptions to depict clouds with greater detail and accuracy. Turner first learned of Howard's work through the second edition of Forster's book in 1821, and it inspired him to paint a series of cloud studies. (Howard also produced a series of his own watercolours depicting the various clouds.)

Cumulostratus by Luke Howard

Later, meteorologists would add an additional category to define the everyday clouds: alto meaning middle. And, like the Linnean system, some cloud forms would be given "species" designating names such as: Cumulus congestus, Cirrus uncinus, Stratus nebulosus.

Other Meteorological Achievements

Although the cloud classification system was Luke Howard's greatest and most enduring achievement, it was not his only one in the field. In fact, in recognition of his contributions to meteorology, the Royal Society elected the amateur meteorologist a Fellow in 1821.

Nor was "On The Modification Of Clouds" Howard's first paper on the atmosphere. In 1800 he had presented a paper on the "Average Barometer" and in 1802 he delivered "Theories of Rain" to the Askesian Society. In 1806 he started his Meteorological Register, which was regularly published in Athenaeum Magazine beginning in 1807.

Howard's study The Climate of London, the first book on urban climatology, was initially published as two volumes during 1818-19, with a second edition of three volumes released in 1833. In it, Howard recognized that cities could significantly alter meteorological elements. One he termed "city fog:"

"...the sky, where any light pervaded it, showed the aspect of bronze. Such is, occasionally, the effect of the accumulation of smoke between two opposite gentle currents, or by means of a misty calm. I am informed that the fuliginous cloud was visible, in this instance, for a distance of forty miles." -- 10 January 1812

Later on 16 January 1826, he would observe another instance of city fog or, as it is now called smog:

"At one o'clock yesterday afternoon the fog in the city was as dense as we ever recollect to have known it. Lamps and candles were lighted in all shops and offices, and the carriages in the street dared not exceed a foot pace. At the same time, five miles from town the atmosphere was clear and unclouded with a brilliant sun."

Howard was also to discover that the urban center was warmer at night than the surrounding countryside, a condition we now call the urban heat island. Under a table presented in The Climate of London (1820), of a nine-year comparison between temperature readings in London and in the country, he commented: "Night is 3.70° warmer and day 0.34° cooler in the city than in the country." He attributed this difference to the extensive use of fuel in the city.

Howard's Seven Lectures In Meteorology were initially given in 1817 and later published as the first meteorological textbook in 1837. Howard also appears to be the first to investigate the influence of the declination of the moon on weather cycles, publishing several papers around 1840. Finally, in 1847 he published Barometrographia.

It also appears that Howard had a rudimentary understanding of what we now know as weather fronts, a concept that did not become well developed until the 1920s. In The Climate of London (1833), he presented a detailed description of cloudiness and precipitation changes which accompanied the replacement of an warm air mass with a colder one, and vice versa. He wrote:

"...if fine hail should fall after a period of damp, sultry weather during which thunderclouds with lightning gather gradually, to be followed by large hail and, finally, rain, and it after this a cold westerly or northerly wind begins to blow, then I would be quite certain that the latter, as a cold body, had suddenly replaced en masse the warm air which was there before the beginning of the thunderstorm.";

For a man who was a successful businessman, devote family man, and pillar in the Society of Friends (the Quakers), Luke Howard always found time to continue his work as a natural philosopher focusing on meteorology. As he remarked late in his life: "meteorology was my real penchant."

"The sky too belongs to the Landscape. The ocean of air in which we live and move, in which the bolt of heaven is forged, and the fructifying rain condensed, can never be to the zealous Naturalist a subject of tame and unfeeling contemplation,"

Howard wrote.

In April of 2002, the British Meteorological Office honoured the memory of Luke Howard by posting a plaque at the north London home at 7 Bruce Grove,Tottenham, where Howard spent his final years. "We are eternally grateful that Luke Howard came up with such an easy and straightforward way of naming clouds," said Mr Michael Fish of the Met Office at the ceremony. Added Emily Cole, Blue Plaques Historian at English Heritage: "Luke Howard's work is of key significance to meteorologists worldwide, and deserves to be better known."

Each time we look out the window and remark on the billowing cumulus, the dull stratus or lacy cirrus, we further honour the name of Luke Howard. He truly deserves the title bestowed by Dr John Day: Godfather of the Clouds.

Learn More From These Relevant Books
Chosen by The Weather Doctor

Hamblyn, Richard: The Invention of Clouds: How an Amateur Meteorologist Forged the Language of the Skies, 2001, Farrar Straus & Giroux; paperback, ISBN: 0374177155. for hardcover edition
Day, John A.: The Book of Clouds , Sterling, 2005, paperback, ISBN 0760735360.

Written by
Keith C. Heidorn, PhD, THE WEATHER DOCTOR,
May 1, 1999