Abstract: Apparatus for breaking up vegetable matter is disclosed. The apparatus may be stationary, material being delivered thereto for treatment, or mobile; e.g., a lawn mower which is moved over a lawn to cut grass. Other mobile embodiments will include apparatus for reaping or harvesting crops more generally. In both the stationary and mobile forms, the apparatus disclosed includes an elliptical blade obliquely mounted on a shaft such that the periphery of the blade generates a cylindrical surface upon rotation of the shaft. Material is cut by the shearing engagement of the periphery of the blade with an edge lying on the cylindrical surface. Cut material is carried into the rotational "cylinder" and discharged radially therefrom. In preferred stationary embodiments of the invention the "cylinder" will be positively defined by a drum having inlet and outlet openings in the cylindrical surface thereof, the openings defining the edge at which initial cutting is effected.

Abstract: An improved compost bin is disclosed and a ventilation channel is formed directly beneath the compost contained in the bin. A tunnel member having a perforated upper portion is contained in the channel to maintain a free passage for air to the base of the heap. The tunnel also prevents the walls of the channel from collapsing and the passage thereby becoming blocked either by the substrate on which the bin is mounted on by decomposing vegetable matter from the bin.In preferred embodiments, end caps are provided to further inhibit the encroachment of the substrate around the walls of and into the tunnel. Holes are provided in a central portion of each end caps to ensure free passage of air.The bin comprises a plurality of similar panels which interengage to form a plurality of vertical sliding joints. The dimensions of the panels and the tunnel are preferably such that, when not in use, the panels may be confined within the tunnel. The bin is normally sold in a kit taking this form.