Bridge of Sighs (Cambridge) Bridge of Sighs (Cambridge) The Bridge of Sighs in Cambridge, England is a covered bridge at St John's College, Cambridge University. It was built in 1831 and crosses the River Cam between the college's Third Court and New Court. The architect was Henry Hutchinson. It is named after the Bridge of Sighs in Venice, although they have little architecturally in common beyond the fact that they are both covered. The bridge, a Grade I listed building, is one of Cambridge's main tourist attractions and Queen Victoria is said to have loved it more than any other spot in the city.
Greenhorn Limestone recognized in the Great Plains Region from Minnesota and Iowa to New Mexico to Montana and the Dakotas. In much of Alberta and Saskatchewan, the "Second White-Specked Shale" contains limy equivalents of the Greenhorn. In Kansas, the Greenhorn Formation is divided into the (lowest) Lincoln Limestone, Hartland Shale, Jetmore Chalk, and (highest) Pfeifer shale members, each noted by changes in chalkiness and limestone rhythmite patterns. In Colorado and western Kansas Hydrocarbon exploration, the divisions are Lincoln Limestone, Hartford Shale, and Bridge Creek Limestone. In other states, where the formation is less developed, the unit is not subdivided and is named