4. A letter from Mr. Jefferson, concerning the success of the GYPSUM, or Plaster of Paris, in Albemarle, Virginia, 200 miles from the sea-coast; also concerning improved hill ploughing, by his ingenious son-in-law, Col. Thomas M. Randolph.[3] [3] See the engraving of Col. Randolph's Hill-side Plough, page 18, vol. IV. Philadelphia Agricultural Society's Memoirs. 5. An American Plough, approved in England; as is our Cradling Scythe. 6. Also, further notice of the Mangel Wurtzel, for the culture of which see the Philadelphia Society's Memoirs, vol. III. Seed of a new kind, called the orange-coloured Mangel Wurtzel, has been sent to President Peters by Robert Barclay, Esq. grandson to the old Apologist of Uri. The progress in the culture of this root, in Great Britain, is great. Mr. Peters thinks the mottled kind best, and recommends the greatest care as to seed. It appears in other parts of this volume that 60 to 90 tons of Mangel Wurtzel, or Scarcity Root, or the improved Beet, have been produced by an acre. 5. In pages 107, 108, 109 and 110, are some interesting notices of the Mangel Wurtzel, or Scarcity or Beet root, by Mr. Isaac C. Jones, of Philadelphia. It appears that this gentleman was led into some experiments, after an entire city occupation of 20 years, by reading some interesting accounts of such experiments in the European books. In April, 1816, a piece of ground, not quite one fifth of an acre, was planted with the seeds, in parallel rows, of two feet three or four inches one way, by one foot the other. On gathering the crop in November, 1816, it was found that it weighed 8180 pounds, and that the weight of the leaves, pulled off from those roots, at different times through the season, was 5,595 pounds. They would have been more, but as the season of 1816 was uncommonly dry, the pulling was omitted for some weeks. This plant is very valuable for farm stock, and _most so for milch cows_. The leaves are excellent through the summer, and the cut or chopped root through the winter, when dry food is used. The Mangel Wurtzel, or Scarcity root or improved Beet, is excellent for the table, and is preferred by Mr. Jones' family to the red or garden beets, which are abundant and very fine in the Philadelphia market. The same gentleman raised in 1816, on 23 square poles (23/160ths of an acre,) 110 bushels of the long or orange Carrot root, being at the rate of nearly 800 bushels to the acre. A bushel of those Carrots (cut with an approved instrument in the form of an S) weighed 47 lbs., and a bushel of the Mangel Wurtzel, cut in like manner, weighed 55 lbs. The Carrots produced 800 bushels, and the Mangel Wurtzel, at this rate, 900 bushels to the acre, each _in the uncut state_. As he planted the Mangel Wurtzel, Mr. Jones found it easy to dress with the plough and one horse. The Carrots, when up, require the hoe and the hand altogether. It appears, that the seeds of this plant, about which the utmost care is necessary,