of the piston in the cylinder, and this has been avoided by the writer in his apparatus by the use of a frictionless piston so arranged as to revolve in the cylinder. A special device to cause it to revolve is not necessary when the dynamometer is used in investigations of steam hauled ploughs, provided it be so situated between the plough and the engine that the cable is connected with the piston instead of with the cylinder. When this condition is fulfilled, the cable, owing to the twist it gets in the making, gives the piston a rotary motion in the cylinder, which begins immediately the cable is taut and continues regularly in the same direction for the whole length of the furrow. The piston moves in the cylinder almost uniformly according to a helicoid line, the pitch of which, though amounting only to a very small fraction of a millimeter, is strictly proportional to the changes in the resistance to traction, because the constant rotary motion of the piston prevents any friction arising.

Handhacken zur Rüben-Kultur.

pp. 43-44. Berlin, February 15, 1913.

Blätter für Zuckerrübenbau, Year XX, No. 3,

By means of the hoe shown in the annexed figure it is possible to work the soil in a circle all round a beet without damaging it. The implement

岡

consists of two blades (c, c) fixed at variable distances on the horizontal arms (bb) of the vertical handle (b), which goes through a socket (a1) of the fork (a). The socket is provided with a rod (aa) which is used to drive the fork into the ground. By shifting the position of the blades plants differing in shape, size and distance apart may be conveniently hoed. When the tool is placed over a plant and the cross- handle is turned, the blades, pointing in or out according as they have been set, loosen the ground in a circle all round.

VOGLINO, E. Il metodo Demtschinsky si può applicare anche ai cereali di primavera. - Il Coltivatore, Year 59, No. 3, pp. 73-79 +5 figs. Casalmonferrato, January 30, 1913. The writer, in discussing the Demtschinsky method (1) modified by Zehetmayr for the cultivation of wheat and of other cereals, mentions a new drill suitable for opening the small furrows in which the seed is to remain covered by a layer of slightly compressed earth as is required by the

above method. This drill, invented by Zehetmayr, is built by Pracner of Raudniz on Elbe (Austria), after whom it is named.

The writer has seen this drill at work in Apulia in the estate of S. Vito dei Normanni belonging to Prince L. di Frasso-Dentice, who used it also in his estates in Moravia and suggested to the maker some improvements, especially regarding the distance between the furrows, which he wants to be eight inches and upwards so as to allow of horse-hoeing.

(1) See No. 1708, B. June 1911.

(Ed.).