Mortar (masonry)
Appearance
![](http://chped.net/https/upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Three_old_bricks_held_together_with_mortar.jpg/220px-Three_old_bricks_held_together_with_mortar.jpg)
Mortar acts as a kind of glue to keep stones and bricks together. When it is used, it is a kind of paste. Some kinds of mortar need to dry before they can act as a glue, in others, a chemical reaction is needed. Certain kinds of mortar can withstand fire for some time. The first kind of mortar was developed in Ancient Rome.