“3. Irregular sound of exhaust--machine will not climb, “4. Popping back of Carburettor, “5. Overheating and knocking, the Instructor is to set up faults for the students to remedy.” He is given ideas for nearly fifteen ways of producing the symptom “Engine won’t start.” “It is suggested that the Instructor should insert a piece of paper between the platinum points in the little magneto, or fit a faulty contact breaker with a stiff rocker in the big magneto, or smear segments and outside of the distributor with a little dirty oil; if he desires to queer the plugs, he may insert one with its gap closed up or bridged with dirt or with a cracked insulation. To produce symptom No. 2, he may insert a punctured float in the Carburettor or insert a piece of rag in the passage between the float chamber and the jets, or block a cock under the Autovac. Or in order to produce an irregular sound in the exhaust and to make the machine refuse to climb, he may remove the roller and pin from one or more inlet valves; or place two faulty plugs in the engine. To make the engine overheat, he is to insert an extra link in the Radiator Fan Bolt, open the Air Slide, or start a leak in one or more of the water outlet elbows. He may make the engine tap and rattle by adjusting the valves with abnormal clearances, and so on with the number of other defects, which each student in turn is to be called upon to diagnose and remedy.” For the conduct of a “Refresher” Battle Practice Course the following points are suggested for the guidance of instructors: “The ammunition required for each man firing will be 20 rounds of shell, 5 rounds of case shot, and 250 rounds of S.A.A. “Before beginning a Battle Practice, the following points must be seen to: “That each practice or scheme is of a practical nature, _i.e._, that it should bring out certain lessons under as near battle conditions as possible. “All ports, etc., in the Tanks will be closed during the practice. Targets should represent as nearly as possible those met with in action. The practice must not be hurried and the Tank must never contain more than the normal crew. Students should be allowed to ride on the top of the Tanks, in order to observe the fire effect. In this way, by observing the faults of others, they should be able to avoid committing the same errors themselves, when their turn comes to fire. “Battle Practice exercises must be regarded by the Tank Crews as what the Field firing practices are to the Infantry. “Vizors and Gas-Masks must frequently be worn during a Battle Practice Course.