for their knowledge of poultry and their acquaintance with poultrymen as well as for special qualifications for their respective departments. =Art.= The illustrating of poultry journals and books, and of the catalogues of fanciers and other advertisers in poultry literature, gives employment to a constantly increasing number of artists. In order to successfully portray birds for critical fanciers, an artist must be something of a fancier. It is not enough that he should draw or paint them as he sees them; he must know how to pose birds of different kinds, types, and breeds so that his pictures will show the proper characteristic poses and show the most important characters to their best advantage. Since the half-tone process of making illustrations was perfected, the greatest demand is for photographic work, but unless an artist is able to work over and complete a defective photograph with brush or pencil, he cannot make this line of work profitable. Most birds are difficult subjects to photograph, and only a small proportion of the photographs that are taken can be used without retouching. A photographer may work for an hour to get a bird posed to suit him, and then, just as he presses the bulb, the bird, by a slight movement of the head or foot, may spoil one feature in a photograph that is otherwise all that could be desired. An artist who can draw birds can remedy such defects; the ordinary commercial artist cannot. =Invention.= The most important invention used in aviculture is the artificial incubator. Methods of hatching eggs by artificial heat were developed independently by the Egyptians and by the Chinese thousands of years ago, and are still used in Egypt and China. The arrangements used in these old hatcheries are crude, and the success of the operation depends upon exceptional skill and judgment on the part of the operator. Operating incubators is a business continued in the same families for centuries. Each hatchery does the hatching for a community. In the early part of the eighteenth century a French scientist named Réaumur, who was much interested in poultry, began to make experiments in artificial hatching and brooding. In 1750 he published a very full account of these and other experiments which he had made with poultry. His idea was to devise a modification of the Egyptian practice of hatching in ovens, suited to the conditions of a more advanced civilization. He succeeded in hatching eggs by utilizing the waste heat from a baker's oven, and also hatched eggs in hotbeds heated with decomposing manure. He applied the hotbed principle to the brooding of chickens with some success. But the methods that he devised were not adapted to general use.