The maintainance of steam in proper shape requires a knowledge of how and when to feed.
The aim in feeding should be to regulate, as nearly as possible, the supply to the demand—just sufficient to keep the water at a proper level in the glass.
This keeps up an even temperature in the boiler plates, tubes and fire-box, and this has much to do with the service of an engine. Many engineers always work their feed in the precise way to get the worst results.
As soon as the boiler is full of steam and blowing off they turn on the pump full and keep it on until the steam is from 30 to 50 pounds below the maximum pressure before turning it off.
This method is the very worst possible. What is wanted is a constant moderate supply of water, keeping the pressure as nearly even as possible. Nothing can beat this.
When injectors are used one of them should be screwed down so that it will act moderately like a pump. This will save the water which is usually lost in turning injector on and off.
On the Foot-plate.
When the train is under full headway the engineer should stand in his proper place on the foot-plate so as to be able to command the regulator and reversing valve at an instant's notice.
Especially is this necessary at night, when the engineer's attention should always be on his engine, listening constantly to its beats to detect any irregularity which may arise from some defect in the machinery, frequently casting his eyes on the pressure gauge, and on the level of the water in the gauge glass.
When the fireman puts on coal, the engineer should look round occasionally, to be sure that he is doing it right, placing the coal next to the walls of the fire-box, and not piling them in a heap in the middle.