NOVELTY - Composting apparatus includes a trough and an apron (28) which is supported in a carriage (27) for travelling along the trough. The apron (28) carries moving rakes (37) which lift and turn the material. It can be set to traverse both backwards and forwards and is angled to a bottom-leading configuration during traversing.    USE - Used for processing farm compost material, e.g. liquid pig manure (claimed).    ADVANTAGE - The apparatus controls and manipulates the process so closely that differences in conditions between different areas of the batch material can be evened out, thus rendering the batch more homogeneous. Concentration can be brought to bear on those areas of the batch where composting is proceeding only slowly, so that all the portions of the batch can gradually be brought to maximum efficiency. The apparatus eliminates the slow-to-react regions, so that the overall time of an aerobic composting session is reduced (from the usual minimum thirty days to, often, as little as twenty days). The apparatus allows the mechanical manipulation needed for mixing the material (which evens out variations in the material), to be combined with the mechanical manipulation needed for turning, lifting, and aerating the material (which promotes the bio-chemical composting reactions).    DETAILED DESCRIPTION - Composting apparatus comprises a trough having walls (25) and a floor (24) for receiving the compost material. It includes a carriage (27), four flanged wheels (29) for guiding movement of the carriage along the length of the trough and a hydraulic motor for driving the carriage into the movement. The apparatus includes an apron (28) which is carried by the carriage (27) and is arranged to move along the trough through the compost material. The hydraulic motor is operable in forward or reverse directions and is structured so that the carriage can be driven in a line from a point A to a point B spaced along the length of the through so that the carriage can be driven in reverse from B to A.    The apron (28) has an angle of inclination relative to the carriage. The apparatus includes rakes (37) for changing the angle of inclination. The apparatus is arranged so that the angle of inclination is changing between an A-B-angle and a B-A-angle, relative to the carriage. The apparatus has an operable device for adjusting the height of the apron where the bottom of the apron can be set to a small clearance distance above the floor of the trough, when the apron moves along the trough. The apparatus is arranged so that in changing between the A-B angle and the B-A angle, the apron passes through an upright position, in which the top of the apron lies vertically above the bottom of the apron. Rakes (37) are operable in conjunction with the operable device for adjusting the height of the apron, to the extent that when the apron is in the upright position, the bottom of the apron can be raised clear of the floor of the trough.    DESCRIPTION OF DRAWING(S) - The figure shows an end elevation of an apron of the apparatus.    Floor (24)    Right walls (25)    Rails (26)    Carriage (27)    Apron (28)    Wheels (29)    Rakes (37)