Abstract: There is disclosed a method for treating waste water containing nitrate ions by subjecting the waste water to decomposition and oxidation to eliminate a harmful gas, the method including the steps of: (a) mixing a waste water containing 10 to 90% by weight nitrate ions in terms of ammonium nitrate with a lower alcohol having 1 to 4 carbon atoms to prepare a mixture, (b) decomposing the mixture at a temperature of 250° C. or higher to generate a decomposition gas, and (c) reacting the decomposition gas with a gas containing oxygen at a temperature of 250° C. or higher to render the decomposition gas harmless.

Abstract: A magnetic display apparatus having a magnetic display sheet consisting of a plurality of microcapsules having oily liquid having photoabsorptive ferromagnetic powder and photoreflective non-magnetic powder, an apparatus for erasing with a magnet a line drawn on the display sheet by the magnetic pen, a magnet, a mechanism for moving the magnet along a major portion of the magnetic display sheet and a power source for moving the mechanism which supports the magnet.

Abstract: A magnetic pen for drawing lines on the main surface of a magnetic display sheet consisting of a plurality of microcapsules in which oily liquid having photoabsorptive ferromagnetic powder and photoreflective non-magnetic powder are mixed in sealed relationship, and wherein the magnetic pen includes a core member having a spherical crown shape, a magnet constituting part of a notched surface of the core member, the core member being supported by the pen such that the notched surface of the core member protrudes from the tip of the pen and a spherical contraposition is generated by a part of the spherical surface of the core member, and wherein the notched surface of the core member is brought into contact with the main surface of the magnetic display sheet by the force of a stroke drawing line.

Abstract: The present invention provides a wind instrument toy having a plurality of melody pipes played by air fed from a blower. A plurality of valves open and close vent portions of the melody pipes. A plurality of vent pipes connect to the corresponding vent portions of the melody pipes and have vertically movable floats therein which float on the air in accordance with music played.

Abstract: A light projecting toy musical box projects a light pattern which is synchronized with musical sound generated by an acoustic mechanism. The projected light patterns are formed by providing a lamp within a base and rotatably mounting a dome over the lamp and substantially on top of the base. The dome is made out of translucent material which is patterned with a semi-opaque coatings so as to form light patterns on the dome itself and project the light patterns on adjacent ceilings and/or walls of a room.

Abstract: A light projecting toy musical box projects a light pattern which is synchronized with musical sound generated by an acoustic mechanism. The projected light patterns are formed by providing a lamp within a base and rotatably mounting a dome over the lamp and substantially on top of the base. The dome is made out of translucent material which is patterned with a semi-opaque coating so as to form light patterns on the dome itself and project the light patterns on adjacent ceilings and/or walls of a room.