Raising torpedoed ships has become a considerable source of increased tonnage for the Allies. According to a report of the British Admiralty Salvage Department, made public June 17, no less than 407 ships sunk by Germans in British waters were salvaged in the years between January, 1915, and May, 1918. Up to December, 1917, 260 ships were recovered. In the first five months of 1918 the number salvaged was 147, the increased rate being due to improved methods. Among the difficulties encountered was the danger of poisonous gases from the rotting cargoes of sunken ships, which sometimes caused the loss of lives. One salvage ship was torpedoed while working on a wreck, and sometimes the work of weeks is destroyed by one rough sea. Feats performed by the Salvage Department include the raising of a large collier sunk in twelve fathoms of water and involving a dead lift of 3,500 tons. Another vessel was raised fifteen fathoms by the use of compressed air. American Exports Versus the U-Boats By CHARLES FREDERICK CARTER Notwithstanding a net loss of the world's shipping, due to the usual perils of the sea as well as to enemy mines and submarines, of 2,632,279 tons from the beginning of the war to April 1, 1918, the vital trade route across the Atlantic has shown a steady increase in efficiency. Even more gratifying is the fact that in recent weeks the gain in efficiency has been accelerated. All the essential requirements of our allies as well as of our own expeditionary forces abroad appear to be met, according to these official statistics from the Department of Commerce. For instance, exports of nitric, picric, sulphuric, and other acids, so essential in the manufacture of munitions, are going to Europe in a steadily increasing volume. Exports of acids increased from a total value of $10,003,647 in the calendar year 1915 to $52,695,640 in 1917. Exports of copper, no less necessary for cartridges and other uses, to France, Italy, and Great Britain increased from 229,129,587 pounds in 1915 to 890,819,053 pounds in 1917. The same three allies, which needed only 499,719 tons of steel billets, blooms, and ingots in the calendar year 1915, took 1,395,019 tons in 1916 and 1,847,201 tons in 1917. Exports of steel plates to the same three allies for ships, tanks, and other military uses increased similarly from 63,584,467 pounds in 1915 to 72,242,656 pounds in 1916 and 165,630,514 pounds in 1917. All Europe took but a negligible tonnage of steel rails in 1913, the last full year before the war. France alone took 5,362 tons in 1915 and 122,858 tons in 1917. Exports of locomotives to France kept pace with the rails, increasing from 38 in 1915 to 570 in 1917, and 129 in the month of January, 1918. Exports of metal-working machinery to these three allies increased from a total value of $29,229,683 in 1915 to $47,666,606 in 1916 and $54,906,405 in 1917.