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:
“See, there is a place by me where you shall stand on the rock; and while my glory passes by I will put you in a cleft of the rock, and I will cover you with my hand until I have passed by;
then I will take away my hand, and you shall see my back; but my face shall not be seen.””
—Bible: Hebrew, Exodus 33:21-23.