We are a firm of engineers, and are constructing a line of railway from X to Z. The l

We are a firm of engineers, and are constructing a line of railway from X to Z. The line passes through several large towns, in each of which we erect a station, and supply the machinery for working the traffic. In the present instance, we are erecting an engine of 120 horse-power, to work the traffic on a branch line, five miles long, from Z to Y.