After Reaumur many others experimented with artificial hatching. Some of the ideas were obviously more impractical than those of Reaumur, but the experimenters tried them out and sometimes succeeded in hatching chickens by very peculiar and laborious processes. One man in England, in the latter part of the eighteenth century, hatched some chickens from eggs placed in cotton batting in a sieve adjusted over a charcoal fire in a small fireplace. The fire was watched constantly for three weeks, either by himself or by some member of his family. He demonstrated that eggs could be hatched in this way, but not that it could be done profitably. Practical incubators were not produced until about forty years ago.
Although incubators and brooders have been brought to a relatively high state of efficiency, they are far from perfect. Inventors of the best machines are still studying ways to improve them. In this and many other fields there are opportunities for inventive genius.
=Education and investigation.= Lectures on poultry have been given occasionally at agricultural institutes in the United States since about 1860. After 1890 the demand for such lectures, and the number given, constantly increased, and ability to speak in public became valuable to one versed in aviculture. Then the study of poultry culture was introduced into agricultural colleges, and a new field was opened to poultry keepers with a faculty for teaching, and for trained teachers with special knowledge of domestic birds. The teaching of poultry culture impressed upon those engaged in it the need of scientific investigation of many problems not clearly understood even by the best-informed poultrymen.
The agricultural experiment stations had been giving little attention to some of these problems except in a desultory way and without important results. As the demands for more accurate information on many topics increased, many of the experiment stations began to make important poultry investigations. For this work men specially trained in various sciences were required. As a rule the men that were secured for such work knew very little about poultry when they began their investigations, but it was much easier for them to acquire a knowledge of poultry sufficient for their needs than for persons who had poultry knowledge and no scientific training to qualify for positions as investigators. The field of investigation of matters relating to poultry is constantly being extended. Proficiency in physics, chemistry, biology, surgery, and medicine, and in higher mathematics as far as it relates to the problems of any of the sciences mentioned, will always be in demand for scientific work in aviculture. In the future the most efficient teachers and investigators will be those whose early familiarity with domestic birds has given a greater insight into the subject than is usually possessed by those who take up the study of the subject comparatively late in life.
=Manufacturing and commerce.= It is very much easier to build up a large business in the manufacture or the sale of articles used by poultry and pigeon keepers than to build up a large business as a breeder of domestic birds of any kind. As has been stated in connection with nearly every kind of bird mentioned in this book, a poultry keeper's operations are limited by the difficulty of keeping large numbers of birds continuously on the same land, and also by the exacting nature of the work of caring for them under such conditions. In manufacturing and commercial operations there are no such limitations. The possibilities of development depend upon the extent of the demand for the articles that are manufactured or sold, and only a small proportion of the employees need to be persons versed in aviculture. But in competition with other manufacturers or merchants those who understand domestic birds and know all the different phases of interest in them have a very great advantage over those who do not.
=Legislation and litigation.= The rise of new industries creates new problems for legislators, executive departments, courts, and lawyers. An industry in which many people are interested eventually reaches a stage where it is profitable for lawyers to specialize to some extent in laws affecting it, and politic for legislators and administrators to do what is in their power to protect the interests of those engaged in it, and to advance those interests for the benefit of the whole community. A special field is opening for lawyers familiar with aviculture and with its relations to other matters, just as within a few years the field has opened to teachers and investigators.
The possible uses of a knowledge of aviculture to young people who are naturally inclined toward intellectual professions, art, invention, manufacturing, or trading have not been given for the sake of urging students to direct their course especially toward work connected with aviculture. The object is only to show those who take an interest in the subject that it is worth while to cultivate that interest for other reasons, as well as for the profit or the pleasure that may be immediately derived from it.