Calendar: 1893-1894 Page 890

clxxii SCIENCE AND SAMBROOKE EXHIBITIONS of mercury till the air within it is compressed to three- fourths of its former volume find the distance of the top of the tube from the surface of the mercury in the tank the height of the barometer being 750 Explain the action of the ordinary air-pump and prove that it is impossible even with the most perfect form of pump to obtain complete vacuum Part II -Heat Describe any method with which you are acquainted for determining the coefficient of linear expansion of solid Explain accurately what is meant by the statement that the coefficient of expansion of air is The volume of certain quantity of air at 50 and 76 cm pressure is 500c determined its volume at and 74 cm pressure Define specific heat body of mass Μ and specific heat at temperature is dropped into mass Jd' of liquid of specific heaty at prove that the final tempera- ture is MxT M'yt M'y י and that if the liquid is water il Θ Describe Regnault's hygrometer and explain how to determine the hygrometric state of the air by its means Part III -Light Sound and Electricity It is desired to throw upon wall an image of an object magnified twelve times the object being 11 ft from the wall find the focal length of concave mirror that may be used for the purpose and state where it must be placed Describe an experiment to show total internal reflection and point out the conditions under which it occurs What is the critical angle for two media State the laws for the frequency of vibration of stretched strings