It may be observed that these teachings are sound and in harmony with the best knowledge of to-day and that they are the very practices which are now being advocated in all dry-farm sections. This is doubly curious because Tull lived in a humid country. However, it may be mentioned that his farm consisted of a very poor chalk soil, so that the conditions under which he labored were more nearly those of an arid country than could ordinarily be found in a country of abundant rainfall. While the practices of Jethro Tull were in themselves very good and in general can be adopted to-day, yet his interpretation of the principles involved was wrong. In view of the limited knowledge of his day, this was only to be expected. For instance, he believed so thoroughly in the value of cultivation of the soil, that he thought it would take the place of all other methods of maintaining soil-fertility. In fact, he declared distinctly that "tillage is manure," which we are very certain at this time is fallacious. Jethro Tull is one of the great investigators of the world. In recognition of the fact that, though living two hundred years ago in a humid country, he was able to develop the fundamental practices of soil culture now used in dry-farming, the honor has been done his memory of placing his portrait as the frontispiece of this volume. CHAPTER XX DRY-FARMING IN A NUTSHELL Locate the dry-farm in a section with an annual precipitation of more than ten inches and, if possible, with small wind movement. One man with four horses and plenty of machinery cannot handle more than from 160 to 200 acres. Farm fewer acres and farm them better. Select a clay loam soil. Other soils may be equally productive, but are cultivated properly with somewhat more difficulty. Make sure, with the help of the soil auger, that the soil is of uniform structure to a depth of at least eight feet. If streaks of loose gravel or layers of hardpan are near the surface, water may be lost to the plant roots. After the land has been cleared and broken let it lie fallow with clean cultivation, for one year. The increase in the first and later crops will pay for the waiting. Always plow the land early in the fall, unless abundant experience shows that fall plowing is an unwise practice in the locality. Always plow deeply unless the subsoil is infertile, in which case plow a little deeper each year until eight or ten inches are reached Plow at least once for each crop. Spring plowing; if practiced, should be done as early as possible in the season. Follow the plow, whether in the fall or spring, with the disk and that with the smoothing harrow, if crops are to be sown soon afterward. If the land plowed in the fall is to lie fallow for the winter, leave it in the rough condition, except in localities where there is little or no snow and the winter temperature is high.