B.—la.

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6. What weight of (a) carbon dioxide (carbonic acid) and (b) water is made by burning 1001b. of marsh gas (CH 4 ) ? 7. Write down the names, symbols, and atomic weights of the non-metallic elements. 8. Write down the names and symbols of the oxides and chlorides of hydrogen, nitrogen, and phosphorus. 9. Describe the process for the manufacture of sulphuric acid. 10. Describe the allotropic forms of carbon or of phosphorus. 11. State what you know of ozone ; how it is made, its properties, and the tests for it.

Class D—Electricity (Optional). Time allowed: Three hours. 1. What is the distribution of electricity on a cube, a sphere, and a disc respectively ? What is the special peculiarity of points, as regards distribution of electricity ? 2. Describe any form of electric machine in which induction instead of friction develops the electricity. 3. How would you make the experiment to show that the electricity in a charged Leyden jar was upon the surface of the glass, and not in the covers ? 4. Describe three essentially different ways of producing a current of electricity. 5. How is an electro-magnet made ? How would you make experiments to illustrate magnetic induction by its means ? 6. Describe a Daniell's, a Grove's, and a Volta cell. In what respects are the two former an improvement on the latter ? 7. Describe the Morse telegraph instrument. What is the use of the relay so often used with it ? 8. Make a sketch showing a section through a Bell's telephone, and state how it differs from Edison's. What are the relative advantages of each ? 9. Describe the process of electrotyping and electroplating. What form of battery is best for the purpose ? 10. Describe a Gramme magneto-electric machine, or any other form of "dynamo" you are acquainted with.

Class D.—Sound and Light (Optional). Time allowed: Three hours. 1. What is the velocity of sound in air? How has it been determined? Upon what does its velocity in any substance depend ? 2. How is a musical note produced in an organ-pipe and in a concertina respectively? 3. What are the fractions that represent the musical scale ? Supposing C to make 256 vibrations a second, what is the length of vibration in the note^ D ? _ 4. State what you know of interference of sound. 5. Give the laws of reflection. Why does a lamp reflected in water often produce the appearance of a streak of light ? 6. Show how it is that a candle, placed a long way from a concave mirror, produces an image that is smaller, and inverted. 7. Show how an image is produced by a convex lens, such as that in a photographic camera ; show also how a convex lens magnifies an object. 8. What will happen when a beam of yellow (sodium) light is sent through a prism? What will happen when a beam of common white light is sent ? Draw a diagram in each case. 9. Give a general account of spectrum analysis. 10. State what you know of interference and polarization of light.

Class D.—Heat (Optional). Time allowed .- Three hours. 1. Describe how the coefficients of expansion of solids and liquids have been determined. Why is the cubic coefficient generally considered three times the linear ? 2. What arrangements are made to compensate for expansion in good timekeepers? 3. How are winds produced? What are the trade-winds? In what direction do they blow? 4. What is the dew-point ? How is it determined ? Upon what does the quantity of dew deposited depend ? 5. What are the various means of producing artificial cold ? Describe any process for freezing meat. 6. What are the varieties of energy ? What is trie energy in gunpowder ? What form of energy is latent heat ? 7. What are the circumstances that influence the boiling of water? What is the difference between boiling and evaporation ? 8. State what you know of radiant heat. If a piece of white paper and a piece of black paper be placed in sunlight, one gets hotter than the other : which? Does the same thing happen if they are placed before a fire ? 9. Eadiant energy manifests itself in three ways —as heat, as light, and as chemical action : how are these distributed in the solar spectrum ? 10. What are the latent heats of water and of steam? If 101b. of water at 30°C, 31b. of ice at 0° C, and 21b. of steam at 100° C. were mixed, what would be the resultant temperature ?