Recently numerous persons have suggested that the expense of running a dry-farm could be materially reduced by using some motive power other than horses. Steam, gasoline, and electricity have all been suggested. The steam traction engine is already a fairly well-developed machine and it has been used for plowing purposes on many dry-farms in nearly all the sections of the dry-farm territory. Unfortunately, up to the present it has not shown itself to be very satisfactory. First of all it is to be remembered that the principles of dry-farming require that the topsoil be kept very loose and spongy. The great traction engines have very wide wheels of such tremendous weight that they press down the soil very compactly along their path and in that way defeat one of the important purposes of tillage. Another objection to them is that at present their construction is such as to result in continual breakages. While these breakages in themselves are small and inexpensive, they mean the cessation of all farming operations during the hour or day required for repairs. A large crew of men is thus left more or less idle, to the serious injury of the work and to the great expense of the owner. Undoubtedly, the traction engine has a place in dry-farming, but it has not yet been perfected to such a degree as to make it satisfactory. On heavy soils it is much more useful than on light soils. When the traction engine works satisfactorily, plowing may be done at a cost considerably lower than when horses are employed. In England, Germany, and other European countries some of the difficulties connected with plowing have been overcome by using two engines on the two opposite sides of a field. These engines move synchronously together and, by means of large cables, plows, harrows, or seeders, are pulled back and forth over the field. This method seems to give good satisfaction on many large estates of the old world. Macdonald reports that such a system is in successful operation in the Transvaal in South Africa and is doing work there at a very knew cost. The large initial cost of such a system will, of course, prohibit its use except on the very large farms that are being established in the dry-farm territory. Gasoline engines are also being tried out, but up to date they have not shown themselves as possessing superior advantages over the steam engines. The two objections to them are the same as to the steam engine: first, their great weight, which compresses in a dangerous degree the topsoil and, secondly, the frequent breakages, which make the operation slow and expensive.