The convenience and versatility of this unit has made it very popular. It consists of a 15x60 cm. wooden board with glass top hinged on an Iron base to which a sector with graduated arc and vertical scale Is provided. The plane may be clamped at any angle upto 45 degree. A 5cm dia frictionless pulley Is attached to the end by means of a clamp adjustable to any necessary position. Complete with brass roller, cart and pan but without weights.