A magnificent piece of Masonry.
--The Union Arch, which spans a gorge over one hundred feet above the bed of the Potomac
, at Cabin Joun Run, seven miles west of Washington
, was planned by Capt. Montgomery C. Meigs
, now Quartermaster General
of the army, and is a triumph of engineering skill.
It is a single arch thrown from the natural abutment of solid rock at the base of one hill to the corresponding one on the other side.--It is a most beautifully proportioned stone arch, of greater span than any other in this country or Europe
That which approaches it nearest in magnificence is the famed bridge of sandstone, across the river Dee
, at Chester
, in England
— a circular arch of two hundred feet span and forty feet rise.
The Union arch is circular (a segment) with a span of two hundred and twenty feet and fifty-seven feet three inches rise.