[6] For a complete list of books for reference, see [p. xii.]
[7] The record time on this route was made by the Lucania in five days, seven hours, and twenty-three minutes, from Daunts Rock, Queenstown, to Sandy Hook light. The fastest day's run yet recorded was made by the Deutschland—601 nautical miles, a speed of 24.19 knots.
[8] In Congress the River and Harbor Bill always receives a generous appropriation.
[9] In many instances goods designed for the spring trade in the Western States are started via the canal in October, reaching their destination at Chicago some time in April, the cargo having been frozen up in one or another of the canal basins during the winter. The rate paid for this slow transit is considerably less than the amount which otherwise would have been paid for storage; moreover, it is nearly all clear profit to the canal boatmen.
[10] The minimum depth of the canal is 22 feet; its width at the bottom is 160 feet. It was begun September, 1892, and completed January 2, 1902, at a cost of thirty-four million dollars. More than forty million cubic yards of earth and rock were excavated. All the bridges crossing it are movable.
[11] This is on the supposition that night travel will be too dangerous a risk. With a continuous travel the time would be about thirty-three hours.
[12] On one great trunk system the average ton-mile rate in 1870 was one and one-seventh cents; in 1900 it was just one-half that sum.
[13] The modern steam-making boiler has from thirty to one hundred or more tubes passing through it from end to end. The heat from the fire-box as a rule passes under the boiler and through the tubular flues; it thus increases the heating surface very greatly. The forced draught is made by allowing the exhaust steam to escape into the smokestack, thereby increasing the draught through the fire-box.
[14] A single locomotive of the New York Central has hauled 4,000 tons of freight at a speed of twenty-five miles an hour. A "camel-back" of the Philadelphia & Reading hauled 4,800 tons of coal from the mines to tide-water without a helper.
[15] The Vanderbilt boiler with cylindrical corrugated fire-box invented by Cornelius Vanderbilt, great-grandson of the founder of the New York Central, marks an important step in locomotive building. The cylindrical form largely obviates the necessity of an array of stay-bolts to prevent warping; the corrugated surface gives greater heating power.