If an engine overheats it is best to check up and see whether or not the car is being operated on a retarded spark or if the mixture is too rich. The usual trouble of the engine overheating are troubles experienced with the cooling system. Fan belts often break or slip, the water may have leaked out somewhere in the cooling system, or the circulation may be stopped up in some way. If anti-freezing mixtures are allowed to remain in the cooling system in warm weather they will cause overheating of the engine due to their low conductivity of heat. Carbon in the cylinder causes the cylinder to overheat and is detrimental to its operation. If the engine is not lubricated properly it will overheat due to the additional friction of the parts. If after the car is in operation the car and engine slow down gradually the trouble is without doubt due to lack of fuel or some trouble with the fuel system or the carburetor. When the car stops under these conditions the engine usually backfires into the carburetor just before the car stops. If the car and the engine stop suddenly it is an indication of some mechanical trouble such as a frozen bearing, broken connecting rod, or some other part which suddenly puts a brake on the movement of the car. If the engine suddenly stops operating and the car continues to coast the trouble can be traced to the ignition system. A disconnected or a broken wire usually causes the trouble. If the engine will not stop when the ignition switch is thrown to the “off” position it is possible with magneto ignition that the cable between the switch and the magneto is broken or disconnected. That is, the switch does not connect the primary of the magneto to the ground. If the engine is overheated, due to lack of proper cooling or carbon in the cylinders, the engine will continue to operate due to the pre-ignition. APPENDIX “A” GUNNERS’ EXAMINATIONS. PREPARATION. In the preparation for the gunners’ examination men should pay particular attention to the following points. Setting the Panoramic Sight. Before starting to use the panoramic sight, the peep sight should be turned as far as possible to the right or left. This should be done to make it easier for the gunner to look through the panoramic sight and also to prevent him from looking through the peep sight.