If you have nothing else to do some day when you are passing through the vast network of subway or railway tracks of any of the great railways running northward or westward or eastward out of New York, give a thought to the man who walks them for you, the man on whom your safety, in this particular place, so much depends. He is a peculiar individual. His work is so very exceptional, so very different from your own. While you are sitting in your seat placidly wondering whether you are going to have a pleasant evening at the theater or whether the business to which you are about to attend will be as profitable as you desire, he is out on the long track over which you are speeding, calmly examining the bolts that hold the shining metals together. Neither rain nor sleet may deter him. The presence of intense heat or intense cold or dirt or dust is not permitted to interfere with his work. Day after day, at all hours and in all sorts of weather, he may be seen quietly plodding these iron highways, his wrench and sledge crossed over his shoulders, and if it be night, or in the subway, a lantern over one arm, his eyes riveted on the rails, carefully watching to see if any bolts are loose or any spikes sprung. In the subway or the New York Central Tunnel, upward of two hundred cannon-ball flyers rush by him each day, on what might be called a four-track or ten-track bowling alley, and yet he dodges them all for perhaps as little as any laborer is paid. If he were not watchful, if he did not perform his work carefully and well, if he had a touch of malice or a feeling of vengefulness, he could wreck your train, mangle your body and send you praying and screaming to your Maker. There would be no sure way of detecting him. Death lurks on the path he travels--subway or railway. Here, if anywhere, it may be said to be constantly lurking. What with the noise, which, in some places, like the subway and the various tunnels, is a perfect and continuous uproar, the smoke, which hangs like a thick, gloomy pall over everything, and the weak, ineffective lights which shine out on your near approach like will-o’-the-wisps, the chances of hearing and seeing the approach of any particular train are small. Side arches, or small pockets in the walls, in some places, are provided for the protection of the men, but these are not always to be reached in time when a train thunders out of the gloom. If you look sharp you may sometimes see a figure crouching in one of these as you scurry past. He is so close to the grinding wheels that the dust and soot of them are flung over him like a spray.