Jefferson, Washington’s great contemporaneous statesman and Virginia planter, and to whom has been ascribed the chief glory of the American patent system, himself also an inventor, enriched his country by the full scientific knowledge he had gained from all Europe of agricultural pursuits and improvements. The progress of the art, in a fundamental sense, that is in a knowledge of the constituents, properties, and needs of the soil, commenced with the investigations of Sir Humphry Davy at the close of the 18th century, resulting in his celebrated lectures before the Board of Agriculture from 1802 to 1812, and his practical experiments in the growth of plants and the nature of fertilisers. Agricultural societies and boards were a characteristic product of the eighteenth century in Europe and America. But this birth, or revival of agricultural studies, the enthusiastic interest taken therein by its great and learned men, and all its valuable publications and discoveries, bore comparatively little fruit in that century. The ignorance and prejudice of the great mass of farmers led to a determined, and in many instances violent resistance to the introduction of labour-saving machinery and the practical application of what they called “book-farming.” A fear of driving people out of employment led them to make war upon new agricultural machines and their inventors, as they had upon weaving and spinning inventions. This war was more marked in England than elsewhere, because there more of the new machines were first introduced, and the number of labourers in those fields was the greatest. In America the ignorance took the milder shape of contempt and prejudice. Farmers refused, for instance, to use cast-iron ploughs as it was feared they would poison the soil. So slow was the invention and introduction of new devices, that if Ruth had revisited the earth at the beginning of the nineteenth century, she might have seen again in the fields of the husbandmen everywhere the sickle of the reapers behind whom she gleaned in the fields of Boaz, heard again the beating on the threshing floor, and felt the old familiar rush of the winnowing wind. Cincinnatus returning then would have recognised the plough in common use as about the same in form as that which he once abandoned on his farm beyond the Tiber. But with the spread of publications, the extension of learning, the protection now at last obtained and enforced for inventions, and with the foundations laid and the guide-posts erected in nearly every art and science by previous discoverers, inventors and writers, the century was now ready to start on that career of inventions which has rendered it so glorious. As the turning over and loosening of the sod and the soil for the reception of seed was, and still is the first step in the art of agriculture, the plough is the first implement to be considered in this review.