BERN-Machine, the name of an engine for rooting up trees, invented by Peter Sommer, a native of Bern in Switzerland.

This machine is represented by a figure on Plate XCV, drawn from a model in the machine-room of the Society for the Encouragement of Arts, &c. It consists of three principal parts; the beam, the ram, and the lever. The beam ABC (no. 1.) of which only one side is seen in the figure, is composed of two stout planks of oak three inches thick at least, and separated by two transverse pieces of the same wood at A and C, about three inches thick. These planks are bored through with corresponding holes, as represented in the figure, to receive iron pins, upon which the lever acts between the two sides of the beam, and which is shifted higher and higher as the tree is raised or rather pushed out of its place. The sides are well secured at the top and bottom by strong iron hoops. The iron pins on which the lever rests should be an inch and a quarter, and the holes through which they pass an inch and a half in diameter. The position of these holes is sufficiently indicated by the figure. The foot of the beam, when the machine is in action, is secured by flukes represented at G, driven into the earth. The ram D, which is made of oak, elm, or some other strong wood, is capped with three strong iron spikes, represented at f, which take fast hold of the tree. This ram is fix or eight inches square; and a slit is cut lengthwise through the middle of it, from its lower end at K to the first ferule a, in order to allow room for the chain g h to play round the pulley K, which should be four inches thick, and nine inches in diameter. This ram is raised by means of the chain g h, which should be about ten feet long, with links four inches and three quarters in length, and an inch thick. One end of this chain is fastened to the top