Agis the son of Pausanias, during an invasion of Mantineian territory once, besieged them and, having turned the flow of the river against the wall, weakened it; for it was of unbaked brick, which is more secure against siege-engines than baked brick and stones. For those break and jump out of their fittings, whereas unbaked brick is not affected in the same way. It is, though, destroyed by water, no less than beeswax [is] by the sun.