Horse-hoeing Husbandry, Or an Essay on the Principles of Vegetation and Tillage, Designed to Introduce a New Method of Culture ; Whereby The Produce of Land Will be Increased, and the Usual Expence Lessened. Together with Accurate Descriptions and Cuts of the Instruments Employed in It. By Jethro Tull, Efq ; of Shalborne in Berkhire. The Fourth Edition, Very Carefully Corrected. To which is Prefixed, a New Preface by the Editors, Addressed to All Concerned in Agriculture