BEFORE attempting to explain the method of composition adopted in landscape gardens of different kinds, a description of the various materials employed is necessary. A striking characteristic of Japanese gardening is the importance attached to the use of natural stones, rocks, and boulders. In a few of the most remarkable European gardens we find rock scenery of considerable grandeur introduced, perhaps the finest example of such treatment being the Buttes Chaumont in Paris. It is also a common practice, in comparatively small gardens of Western design, to arrange rockeries and fancy grottoes principally for the purpose of planting them with ferns and mosses. With rare exceptions, however, such rock-work consists of formless blocks of slag and broken stone held together with earth, and displaying but little regard to form or proportion.