Annual report upon explorations and surveys in the department of the Missouri . Fie. Fig. II. 1800 REPORT OF THE CHIEF OF ENGINEERS. slope being too nearly a vertical, and without any bank by the water, a passsage wasconstructed in a part of the river-bed for a distance as great as several hundred yardsin the shape of a pier. These viaducts were of superior workmanship, the height variedfrom 8 to 10 feet, and with the side slope from the bottom commensurate with thestrength and endurance required, the top surface was at the widest points at least 10feet across. (See Fig. II.) Mr. Wightman
Annual report upon explorations and surveys in the department of the Missouri . Fie. Fig. II. 1800 REPORT OF THE CHIEF OF ENGINEERS. slope being too nearly a vertical, and without any bank by the water, a passsage wasconstructed in a part of the river-bed for a distance as great as several hundred yardsin the shape of a pier. These viaducts were of superior workmanship, the height variedfrom 8 to 10 feet, and with the side slope from the bottom commensurate with thestrength and endurance required, the top surface was at the widest points at least 10feet across. (See Fig. II.) Mr. Wightman stated the cost of construction of the via-ducts of the average dimension, 10 feet at base, 8 feet on a vertical, and 8 feet wide attop, to be $ per linear foot. At some points this was exceeded, the river with arapid current and a depth of 6 feet, occupying the place where the road now the blasting was also very expensive from the flint-like nature of the quartzite,the working being so difficult that 30 steel drills per foot were used. The most ex-pensive filling of
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