OUTLINES OF THE ATMOSPHERIC BRAKE.
Although the automatic air-brake is now becoming almost universal in American railroad practice, most train men are familiar with the working of the atmospheric brake under the name of “straight air.” When first invented, the Westinghouse brake consisted of an apparatus located on the locomotive for compressing air, which was stored in an iron drum fastened somewhere about the engine. Underneath each car, and connected with the ordinary brake attachments, was a cylinder containing a piston, which operated the brake. The brake-cylinders were kept in communication with the air-drum on the locomotive by iron pipes. Connection between the cars where “stretching” and “compression” made the train vary in length, was made by means of rubber flexible hose. When the engineer wished to apply the brakes, he admitted the compressed air into the supply pipes, through a three-way cock at his hand. This air entered the cylinders under the cars, moving back the pistons which pulled the levers operating the brakes. To release the brakes, the air was permitted to escape out of the pipes into the atmosphere.
Thus, what is really a complicated operation was performed in a simple manner, and by means of machinery not liable to get out of order readily. The instant application of every brake on a long train was put in the hand of the engineer. On the first indication of danger, his hand became powerful beyond the magical forces conceived by the imagination of poets.