Various opinions have been expressed as to this. It has been estimated that the amount of heat arising from the stream on a winter's day, is sufficient to raise the atmosphere over the British Isles from the freezing point to a summer temperature. How may the Gulf Stream be distinguished? It can be distinctly traced in the ocean by its dark indigo color, its temperature, and the swiftness of its waters. Which is the largest tunnel in the world? The Mt. Cenis Tunnel, or the tunnel of Col de Frejus, by both of which names it is known. It is the longest subterranean route for commerce and travel yet constructed, being 7-1/4 miles in length. It is on the crest of the Cottian Alps, about 16 miles south-west of the summit of Mt. Cenis Pass. It was begun in 1857, and finished in 1871. _Col_, a defile. What other great engineering work can you mention? The Suez Canal, a ship canal running across the Isthmus of Suez, and connecting the Mediterranean with the Red Sea. The canal is 100 miles in length, and through it an uninterrupted communication is established whereby large sailing vessels and steamers may pass from sea to sea, and thus avoid the long and dangerous voyage around the Cape of Good Hope. To whom is the world indebted for this canal? This great work owes its inception and completion to the enterprise and indomitable energy of Ferdinand de Lesseps, who was born at Versailles, France, on the 19th November, 1805. In January, 1856, he obtained a charter from the Egyptian Government for a company to construct the canal, and began work in 1859. Though beset by many difficulties, the persistent energy of De Lesseps fought its way to success, and in 1869 he had the satisfaction of seeing the waters of the Mediterranean and the Red Sea mingle in the Bitter Lakes. He has since been engaged in many engineering projects, the latest being a canal across the Isthmus of Panama to connect the Atlantic and Pacific oceans. _Inception_, beginning. _Indomitable_, not to be subdued. _Persistent_, inclined to hold firm. What is a Suspension Bridge? A bridge supported by wires, ropes, or chains, which usually pass over high piers or columns at each end, and are secured in the ground below. Name some of the largest bridges of this kind. That at Niagara, those over the Allegheny at Pittsburg and the Ohio at Cincinnati, and the great East River bridge, which connects New York and Brooklyn. Who planned these bridges? John A. Roebling, who was born at Mulhausen, Prussia, June 12, 1806. In 1831 he emigrated to this country, and to his genius we are indebted for the bridges above named. The reports, plans, and specifications of the East River bridge were completed, and the work begun, when Roebling was severely injured in the foot while directing his work. Lockjaw succeeding amputation, he died in Brooklyn, July 22, 1869. To what great Civil Engineer has the West given birth?