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.
Sheet music first printed sheet music made with a printing press was made in 1473. Sheet music is the basic form in which Western classical music is notated so that it can be learned and performed by solo singers or instrumentalists or musical ensembles. Many forms of traditional and popular Western music are commonly learned by singers and musicians "by ear", rather than by using sheet music (although in many cases, traditional and pop music may also be available in sheet music form). The term "score" is a common alternative (and more generic) term for sheet music, and there are several types