As soon as the engine is run into the engine-house, all superfluous grease which has escaped from the wearing surfaces and the dust or mud which adheres to the engine should be wiped off with cotton waste or rags. This is usually done by men employed for the purpose. While they are doing this, they should examine every part thoroughly and observe whether it is in good condition, and if any defects are found they should be reported to the proper person whose business it is to have them repaired. As the faithfulness and skill of a fireman are often estimated by the good or bad condition of his engine, he should, if for no other reason, take pains to keep it clean and everything in as good condition as possible. If the engine is taken to pieces in order to be thoroughly repaired, the runner, if he does not help to do this, should watch carefully the taking it apart and the putting it together again, as in this way he can become thoroughly familiar with the construction of the machine he runs. QUESTION 501. _What precaution must be taken to prevent the water in a locomotive from freezing, if it is laid up?_ _Answer._ In very cold weather, if engines are laid up for any considerable time, no water must be left in the tender, boiler or any of the pipes. If, however, the engine must be soon used, and it is impracticable to let the water out of the boiler and tender, then, if exposed to the cold, a light fire must be kept in the boiler sufficient to make steam enough to warm the water in the tender. The water should, however, be drawn out of the pumps and the feed and supply pipes. This can be done by opening the pet-cocks, and closing the tender valves and uncoupling the hose, which will allow the water in the supply pipes to run out. By running the engine a few revolutions the pumps will then be emptied. The pipes and the pumps can also be prevented from freezing without uncoupling the hose if the tender valves are closed and the pet-cocks opened, and steam is then admitted into the supply pipes by the heater-cocks. This forces part of the water which is in the pumps out of the pet-cocks and warms the rest. This, however, requires constant watchfulness to prevent freezing, and in excessively cold weather, if the engine must lay up for any considerable time, it is always best to empty the pumps and pipes. PART XXVIII. ACCIDENTS TO LOCOMOTIVES. QUESTION 502. _What are the most serious accidents which may happen in running a locomotive?_ _Answer._ The most serious accidents are: 1. Collision of two trains approaching each other. 2. Collision of a moving with a standing train. 3. Collision of trains at the crossing of two railroads. 4. Running a train into the opening left by an open draw-bridge. 5. Escape of an engine without any one on it. 6. Running off the track. 7. Explosion of the boiler. 8. Bursting or rather collapse of a flue. 9. Blowing out of a bolt, stud or rivet from the boiler.