Engineering Wonders of the World
Volume III

170 ENGINEERING WONDERS OF THE WORLD. The drivers are usually mounted on wheels with a 19-foot gauge, and upon the frame- work is another set of wheels Pile Driving. p|acej transversely to the first, enabling the whole outfit to travel back and forth over the work, or permit the leads to travel in a transverse direction to cover a line of piles 20 feet or more long at every for- ward move of the driver. In an eight-hour day one hundred and eighteen 25-foot piles can be driven. The sand and gravel washing and screening plants are also of interest. These plants are located on the sides of hills, at the top of which are the sand and gravel Screening1, pits. orange-peel bucket Criishing, and |oa(|g excavated material Washing . Plants mto dump-wagons, which haul it to a set of “ grizzlies,” which reject all stone over three inches, and drop the small stuff through chutes to a jaw-crusher below. From the crusher the stone falls into the boot of a bucket-elevator, which hoists it to the storage-bin. The sand and gravel coming into the grizzlies pass on to a rotary screen, in which a jet of water is made to travel in the direction opposite to the move- ments of the sand and gravel. The sand drops into a hopper, and a screw conveyor carries it under water to a bucket-elevator, which deposits it in the storage-bin. The gravel goes direct to the bin, and the rejec- tions (stones over two and a half inches) go to th© crusher. The concrete-mixing plants are built by individual contractors for work under their respective contracts. An elevated storage- bin, a mixer, and storage space on either side for sand constitute the principal features of these plants, which are driven by electricity. The stone and sand are dropped into measur- ing-boxes, and the cement added, mixed, and discharged into buckets on flat cars. Another important canal is the Sault Ste. Marie, forming the northernmost link in the chain of inland waterways. Between two of the Great Lakes, Superior and Huron, we find a district teeming with the bustle, Sault Ste. Marie Canal. energy, and goodwill of a healthy interna- tional commerce, and a canal once described by one of America’s greatest statesmen as a “ work beyond the remotest settlement in the United States, if hot in the moon ! ” In 1836 Michigan was initiated into the mysteries of statehood. In 1837, the first governor in his first message to the first Legislature of that State urged the immediate construction of a canal to assist in distributing the natural Resources of that section—copper, iron, fisheries, furs, pine, timber, and farm products. Yet, notwithstanding this known wealth, and the enlistment of neighbouring States in the canal petitions, Congress could not be persuaded to loosen the national purse- strings. It did, however, present the canal interests with a land grant of 750,000 acres. Meanwhile, commercial interests were chafing under the repression of the possible boundless traffic. So a contract was agreed upon, which provided that the contractors, in considera- tion of the 750,000 acres, should construct within two years the long-wished-for canal between the two lakes. The canal was to have two consecutive locks, 350 feet long, 70 feet wide, and 13 feet deep. The width of the canal was to be 100 feet, and the calculated cost was $557,739. The actual cost of the first attempt, however, was $999,803.46. In June 1853 work began, and on April 19, 1855, the first boat passed through the locks of the now famous St. Mary’s Ship Canal. Twelve years later the im- mediate enlargement of the Enlarging . , . the Canal canal became necessary to anj Locks meet the insistent demand of the outside world for a share in the mineral wealth lying in the vicinity of the canal.