sentences:  it is a marl, or limestone containing integral clay, dug out of the ground, burnt and ground to a fine powder).In 1791, Parker was granted a patent "Method of Burning bricks, Tiles, Chalk".His second patent in 1796 "A certain Cement or Terras to be used in Aquatic and other Buildings and Stucco Work", covers Roman cement, the term he used in a 1798 pamphlet advertising his cement.