Cloud atlas was published in 1802. It followed a similar effort in French by Jean-Baptiste Lamarck in 1801. Howard's nomenclature defined four fundamental types of clouds: cirrus or thread-cloud, cumulus or heap-cloud, stratus or flat cloud (level sheet), and nimbus or rain-cloud (see Classification of clouds). There followed a long period of development of the field of meteorology and the classification of clouds, leading up to 1896, the International Year of Clouds. The history of this period is the subject of a popular book, "The Invention of Clouds". During that time, the Englishmen Rev. Clement Ley and Hon. Ralph Abercromby, were influential.
Cloud and stratiform characteristics in the form of rolls, ripples, or elements. They generally form as a result of "limited convection" in an otherwise mostly stable airmass topped by an inversion layer. If the inversion layer is absent or higher in the troposphere, increased air mass instability may cause the cloud layers to develop tops in the form of turrets consisting of embedded cumuliform buildups. The stratocumuliform group is divided into cirrocumulus (high-level), altocumulus (mid-level), and stratocumulus (low-level). Cumuliform clouds generally appear in isolated heaps or tufts. They are the product of localized but generally "free-convective" lift where there are no