A manhole cover is a removable plate forming the lid over the opening of a manhole, to prevent anyone or anything from falling in, and to keep out unauthorized persons and material.
They date back at least to the era of ancient Rome, which had sewer grates made from stone.
Read more about Manhole Cover: Description, Circular Shape, Manhole Covers and Race Cars, Propelled Into Space, Other Uses, Gallery
Famous quotes containing the word cover:
“Laid out for death, let thy last kindness be
With leaves and moss-work for to cover me:
And while the wood-nymphs my cold corpse inter,
Sing thou my dirge, sweet-warbling chorister!
For epitaph, in foliage, next write this:
Here, here the tomb of Robin Herrick is.”
—Robert Herrick (1591–1674)