Among the machines requiring a considerable investment for the number of days used may be mentioned hay loaders, hay tedders, corn-binding harvesters and lime spreaders. There is a certain class of labor-saving devices, however, for which there is more or less constant need, as, for example, means of pumping water, methods of handling manure, both from the stable to the manure shed, and from the manure shed to the field. This leads to the remark that there is at present great need of modifying our traditional ideas concerning farm barns. Why do persons usually sleep on the second floor, while horses and cattle are placed in the basement? Three things have brought about the need of a radical revision of our practices concerning the planning of barns: (1) Our present knowledge of the difference in the function of food in keeping the animal warm, and that of producing work, flesh or milk; (2) the discovery of the bacillus of tuberculosis; and (3) the invention of the hay carrier. It is not the purpose here to discuss barn buildings, but merely to call attention to the fact that the traditional barn has long since outlived its usefulness, and that the young farmer should plan his farm buildings to serve the purposes required in the light of modern knowledge. Various attempts have been made to manufacture combined machines; that is, a machine which, by an interchange of parts or other modification, may be used for two or more purposes, as, for example, harvesting small grain and cutting grass. Such attempts have usually been unsuccessful. On the other hand, the young farmer should consider the range of usefulness of any given type of machine or tool; thus, a disk harrow is more efficient for some purposes than a spring-tooth harrow. For other purposes the spike-tooth harrow is better than the spring tooth. The spring-tooth harrow, however, will do fairly well wherever the disk harrow or the spike-tooth harrow is needed. When, therefore, only one of these tools can be afforded, the spring tooth may be a better tool to buy than either the disk or the spike-tooth, although it is not for certain purposes as efficient as either of the others.