Page:Popular Science Monthly Volume 45.djvu/481

Rh do the most good, or at least where it would not be used to kindle the kitchen fire.

The above suggestions refer solely to those reports which tend to the advancement of human learning, and, printed and distributed freely as they are by the nation, should reach in every case those who stand most in need of them.



N the 19th of September, 1891, Sir Henry Tyler, President of the Grand Trunk Railway Company, presided at the inauguration of one of the greatest engineering achievements of the present day, bold in conception, new in design, and novel in many of the methods adopted in its construction. Without the St. Clair Tunnel the immense stream of traffic from the East, which during last summer flowed to the World's Columbian Exposition at Chicago, could not have been successfully handled.

Previous to the construction of the tunnel, connection between the Grand Trunk Railway and the Western roads with which it exchanges traffic was maintained by a ferry, the loaded cars being carried across on the deck of a powerful steamer, specially built for the purpose. Adopted for want of a better, this service was never satisfactory. Though the swift current, where Lake Huron pours its entire volume through a narrow outlet, prevents the river freezing in winter, ice blocks occasionally occurred, and a single day's interruption to traffic involved serious inconvenience and loss. A bridge had often been suggested, but it was always successfully opposed by the vessel interest. A larger number of vessels, with a greater tonnage, pass up and down the St. Clair River during the season of navigation than through the Suez Canal in a year. A high-level bridge is impossible, and a draw would be attended with great interruption to traffic, and danger to vessels on account of the current. The only alternative seemed to be a tunnel. Its completion not only affords a better crossing, but establishes the possibility of such a work being successfully and economically built and worked where favorable conditions exist. The story of its construction is an interesting one.

The tunnel is really a large iron tube, twenty feet in diameter and six thousand and twenty-six feet long, buried under the river, but considerable ingenuity was required to place it there. In 1884 Mr. Joseph Hobson, the chief engineer of the work, and Mr. Hillman, his assistant, made a survey of the river, one mile 