C—3;

Subject B. — Amalgamating-machines.

1. How is amalgamation effected in the mortar-box of a stamp mill? Describe fully. _ 2. State what amalgamating-machines you have used; their action, speed, capacity, and horse-power required to work them. . 3. Give the dimensions of a settler, its use, and the number of revolutions per mmute as being the most economical speed that it should be worked at. 4. Give the speed and capacity of a combination pan, McKay pan, and Watson-Denny pan; the quantity of pulverised ore that each would treat in twenty-tour hours, and the horse-power required to work them. Subject C— Quicksilver, and the Methods of using it in connection with the Extraction of Gold and Silver from Ores. 1. State the quantity of quicksilver you would use for amalgamation in a combination pan, Watson-Denny, and in a McKay pan, and state your reasons for same. 2. Describe how you would coat copper plates with quicksilver; how you would remove the bullion from the plates, and how you would keep the quicksilver in a lively condition. 3. What effect has ore containing lead, antimony, and copper on quicksilver ? 4. State how you would remove all base metal and impurities from quicksilver. Describe 5. Describe fully the method you would adopt in cleaning up, and how you would separate the bullion from the quicksilver and put in a marketable condition. Subject D.— Cyanide, Chlorination, and other Chemical Processes of recovering Gold and Silver from Ores. . • 1. Give a sketch of cyanide plant with four percolating-vats, showing all dimensions, and the relative position in which you would place sumps and all appliances for a complete plant. 2. State how you would ascertain the strength of KCN solution, and also the strength of the solution that is most economical to use with ore you are treating. 3. How many tons of a solution containing 12 per cent, of KCN would you require to make up 40 tons of a sump solution containing 0-012 of KCN to a 025 solution? 4. How many pounds of crude salt containing 65 per cent, of KCN would be required to make up 14 tons of a stock solution containing 15 per cent, of KCN ? 5. If there were 50 tons of a sump solution containing 001 per cent, of KCN, how many pounds of crude salt containing 75 per cent, of KCN would be required to make up a 0-3-per-cent. solution ? 6. How many tons of 0-9 per cent. KCN solution would be required to make up the strength of 30 tons of sump solution containing 0-12 per cent, of KCN to a 03-per-cent. solution? 7. If dry pulverised ore had a weight of 100 lb. per cubic foot, show by calculation the number pf tons of 2,240 lb. there would be in a vat 30 ft. in diameter and filled, with ore to a depth of 4 ft. 7$ in. . . 8. A sump 26 ft. 4| in. in diameter and 6 ft. deep : show by calculation the number of imperial gallons it would contain. ' , 9. Describe fully the remedies you would apply if any of the workmen were suffering from cyanide poisoning. 10. How is chlorination effected ? Describe fully the process which ores containing gold are subjected to. 11. Describe the process of making chlorine solutions, and how these are used to extract the gold from auriferous ores. 12. Describe the difference between a Newberry-Vautin chlorination and a plant required to chlorinate ores by the Plattner process. 13. Describe fully how gold is precipitated from cyanide and also from chlorine solutions. 14. Describe fully how you would recover gold from chlorine solutions, and also bullion from cyanide solutions, and put it in a marketable condition. Subject E.— The Sampling and Testing of Ores. A hundredweight of lode stuff is sent to a mill for valuation: describe in detail how you would proceed in order to make a report on its value—giving reference to your own experience. Subject F.— Knowledge of Arithmetic and Method of keeping Battery Accounts. 1. If 700 oz. of bullion contained gold 0-2354, and silver 05345, find what would be its value, taking pure gold to be worth £4 4s. per ounce and silver 2s. 4d. per ounce. 2. The wages in a battery for one month where 23 workmen were employed amounted to £275 There were four divisions of the men, A, B, C, D : 9 men in A division got twice as much as the 7 men in C division; 4 men in B division got £25 less than the men in C division; and 3 men in D division got one-half as much as the men in C division. How much did each man receive ? 3. A round spar 70 ft. in length was 25£ in. diameter at the one end and at the other. Give its measurement in cubic feet. 4 Show how you would enter the following accounts in journal, cash-book, and ledger. The goods received were—H. Jones, 10 shoes for stamps, £21 Bs. Id.; 500 lb. KCN., £29 3s. 4d.;

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