††††Cement is any bonding agent used to join bricks or other materials together.
The first mortars used to cement bricks together in Mesopotamia were mud and tar. Sometimes tar would be mixed with sand and gravel to produce a substance known as mastic. Plaster could sometimes be made if limestone or gypsum was available. The Romans made the first true cement, which works by including water in its structure rather than letting it evaporate.
Modern Portland cement is a powder made by burning together lime (or chalk) and clay. When mixed with water and sand or gravel the cement turns into mortar or concrete.
