Calendar: 1880-1881 Page 686

686 CL OTHWORKERS SCIENCE EXHIBITIONS IV &pt ro$tattt$ Pneumatics fetat antt Htgijt Describe the construction and explain the action of Bramah's Hydrostatic Press slab of Portland stone of specific gravity 2Ί length feet breadth feet and thickness inches is lowered by rope vertically in water so that the upper end is just level with the water find the strain on the rope the pressure of the water against the two sides and the pressure against the lower end Describe three experimental methods of obtaining the specific gravity of substance lighter than water Enunciate Boyle' law and shew how its truth may be proved for pressures greater for pressures less than that of the atmosphere Describe the construction and explain the action of the Fire Engine Explain clearly the action of the Syphon It is required by means of pump to raise water to the top of house 30 feet in height Sketch form of pump which would suffice and find what pressure per square inch would be exerted on the piston Give an account of the method adopted by Lavoisier and Laplace for determining the linear expansion of metal bars How is it that different observers get different results in investigations of this kind Compare the weight of 1000 cubic centimetres of air at 10 and 760 pressure with the weight of 5000 cubic centimetres at 20 and 720 pressure 10 Give description of the most accurate form of instrument with which you are acquainted for determining the hygrometric state of the air and shew clearly how the instrument should be used for this purpose 11 Explain the action of Davy's safety lamp 12 Describe some one of Joule's methods of determining the Mechanical Equivalent of Heat and state the results arrived at