Abstract: An educational apparatus includes a housing having a front wall with laterally spaced arrays of sensing and positioning holes and sets of letter or number display members each including one or more positioning pins and one or a pair of differently spaced and located positioning pins projecting from the rear faces of the display members, the pins being slidably engageable with respective holes. A switch matrix is located behind each hole array and is connected to the input of a calculator or message enunciating network located in the housing and having an output connected to LCD's on the housing front wall and/or to a transducer speaker in the housing. Calculator function switch buttons are located on the front wall.

Abstract: An apparatus for containing and cleaning up an oil spill at an offshore oil platform in a body of water includes a hollow circular ring surrounding the oil rig and supporting a depending frustoconical skirt wall anchored to the ground by biasing springs which permits the vertical movement of the ring and skirt wall with variations in the water level. A second hollow ring is connected to the first ring by a peripheral skirt wall which confines oil floating on the water surface. A tanker along the side of the rings sucks up the ring-confined oil by suction pumps and stores and removes the oil. In an alternative form, the first skirt wall is formed of an elastomeric web and stays extending obliquely along the wall face between ground and the first ring biases the wall and ring downwardly.