Abstract: Weighing scales for use as a teaching aid in educational establishments. The scales include a platform adapted to receive an article to be weighed, a compressible, fluid-containing reservoir, in the form of bellows or diaphragm provided with a fixed wall. The scales are provided with display means which are in fluid communication with the reservoir. The display means is a transparent flexible tube adapted to display the volume of fluid displaced in response to the article being placed upon the platform.
Abstract: The invention relates to an eductional aid for teaching children to tell the time. The aid includes a face and at least one pointer rotatable about a centrally disposed axis relative to the face. A carrier is provided which carries indicia which are position behind the face. The face includes apertures through which at least some of the indicia can be seen. A knob for moving said carrier is also provided so that the indicia may be selectively displayed through the apertures.