Chester Rows east side of Northgate Street. Originally there were also Rows in Lower Bridge Street but these were blocked during the 17th and 18th centuries. As the ground floor buildings are usually lower than the street level, they are sometime known as "crypts". However, as the architectural historian Nikolaus Pevsner points out, this is not a strictly accurate description because the level of the floors of the buildings is a half-storey rather than a full-storey level below the street. Rows were built in the four main streets leading from Chester Cross, each of which originated during the settlement's early development. In
Whiskers them understand how biological whiskers work and as a tactile sense for robots. These efforts range from the abstract, through feature-specific models, to attempts to reproduce complete whiskered animals in robot form (ScratchBot and ShrewBot, both robots by Bristol Robotics Laboratory). A range of non-mammalian animals possess structures which resemble or function similarly to mammalian whiskers. Some birds possess specialized hair-like feathers called rictal bristles around the base of the beak which are sometimes referred to as whiskers. The whiskered auklet ("Aethia pygmaea") has striking, stiff white feathers protruding from above and below the eyes of the otherwise slate-grey bird,