Clouds. The varied forms of the clouds depend upon the modes of their formation - that is, whether they are condensed into visible forms in a quiet or a disturbed atmosphere. It is likely also that the electrical condition of the vapour itself may have an influence upon the shape it may assume. The cloud is a collection of vapours suspended in the atmosphere, and consists chiefly of water converted into the gaseous form by heat. The round massive cloud which looks like a distant mountain is called cumulus. The name is a Latin work, signifying a heap, and is the derivative of accumulation, The flat long cloud is called strains, a layer (hence the word stratification, etc.) The feathery cloud, like a colt's tail, is called cirrhus, a beard. When the stratus intersects the cumulus, the combined form is called nimbus (a shower), from its producing rain.