in speed was hardly perceptible, the more rapid exhaust told the story of faster movement.  As the train sped on, the engineer moved the reversing-lever notch by notch nearer the centre of the guide.  This adjusted the “link-motion” mechanism, which is operated by the driving-axle, and cut off the steam entering the cylinders in such a way that it expanded more fully and economically, thus saving fuel without loss of power.

When a station was reached, when a “caution” signal was displayed, or whenever any one of the hundred or more things occurred that might require a stop or a slow-down, the engineer closed down the throttle and very gradually opened the air-brake valve that admitted compressed air to the brake-cylinders, not only on the locomotive but on all the cars.  The speed of the train slackened steadily but without jar, until the power of the compressed air clamped the brake-shoes on the wheels so tightly that they were practically locked and the train was stopped.  By means of the air-brake the engineer had almost entire control of the train.  The pump that compresses the air is on the engine, and keeps the pressure in the car and locomotive reservoirs automatically up to the required standard.

Each stage of every trip of a train not a freight is carefully charted, and the engineer is provided with a time-table that shows where his train should be at a given time.  It is a matter of pride with the engineers of fast trains to keep close to their schedules, and their good records depend largely on this running-time, but delays of various kinds creep in, and in spite of their best efforts engineers are not always able to make all their schedules.  To arrive at their destinations on time, therefore, certain sections must be covered in better than schedule time, and then great skill is required to get the speed without a sacrifice of comfort for the passenger.

To most travellers time is more valuable than money, and so everything about a train is planned to facilitate rapid travelling.  Almost every part of a locomotive is controlled from the cab, which prevents unnecessary stopping to correct defects; from his seat the engineer can let the condensed water out of the cylinders; he can start a jet of steam in the stack and create a draft through the fire-box; by the pressure of a lever he is able to pour sand on a slippery track, or by the manipulation of another lever a snow-scraper is let down from the cowcatcher.  The practised ear of a locomotive engineer often enables him to discover defects in the working of his powerful machine, and he is generally able, with the aid of various devices always on hand, to prevent an increase of trouble without leaving the cab.