wo shore-spans of 150 feet each, covered by fixed trusses, and a draw 500 feet in length; can be opened and closed in two minutes; bridge authorized by act of Congress June 16, 1886; completed at a cost of $450,000, June 13, 1888.
Wooden bridge, over the Connecticut at Hanover, with a single arch of 236 feet; erected in 1796.
Potomac Run Bridge, a famous trestle-work 400 feet long and 80 feet high; built in nine days by soldiers of the Army of the Potomac under the supervision of Gen. Herman Haupt.
It contained more than 2,000,000 feet of lumber, chiefly round sticks, fresh cut from the neighboring woods; erected May, 1862.
Portage Bridge, over the Genesee River, on the line of the Erie Railroad at Portage, N. Y. An iron truss bridge on iron trestles, built in 1875, to replace the original wooden trestle bridge; completed Aug. 14, 1852, and burned down, May 6, 1875; total length, 800 feet, comprising one span of 180 feet, two of 100 feet, and seven of 50 feet; height, 130 fe
t at a cost as yet unestimated.
As for the San Francisco embankment line, General Hains regards it as the most dangerous matter in connection with the whole project.
General Abbott, who, however, represents a rival project, says that enormous embankments are required in the San Francisco basins.
They are sixty-seven in number, and 6 miles in length, and some of them will rise from 60 to 85 feet above soft mud, which must be excavated to a depth of 30 feet to reach a clay foundation.
Professor Haupt, a member of the Walker board, says that there are some 8 miles instead of 6 of artificial work along the entire length of the line of the San Francisco Basin.
The canal board, at the head of which was Gen. William Ludlow, expressed grave doubts, similar to those expressed by the Walker board, as to the risk and possible trouble that would arise under the Menocal plan.
After the canal board, which had neither the time nor the money to make an examination such as was needed, but