Pkimitive Gri;i;ce: Mycenian Art, because they were immediately covered with ruin and soil when the building collapsed. That the wall was made of mud is plain ; and is further proved by the fact that around the channel-Uke cavities, the mortar which served to join the bricks is like these baked or rather burnt. At first Schliemann thought that these erections had some analogy to the " vitrified forts," ' as they are called, that have ■'%C^_jf_^:j{ Fic. 51.— Wall of crude brick. been discovered in Scotland and France. If the fire, he argued/ thus far modified the condition of the clay of brick and mortar, it was because the builder had purposely set fire to it himself, having previously filled these channels with chips and faggots, in order that his wall should become more compact and abiding. Better informed by his researches at Tiryns, M. Dorpfeld pointed out ' A list of the princiiial works dealing with these circuit-walls, down to 1872, will be found in a Memoir by M. J. Marion, Z« mo>iumenls celtiques et icmidinmts its environs ^Inverness.
