Special bricks were made for a number of purposes, such as plinths, chamfered corners, moulded widnow and door jams. Some of the more precise shapes were required for building circuar chimneys to fine tollerences, including curved and tapered bricks, sometimes with different arcs used fur chimneys which taper, tighter curves at the top and almost straight sided at the bottom. some tapered bricks
might have been cut after pressing, but before firing, but many machine brickworks has a range of special moulds for the various shapes. The special curved and tapered chimney bricks appear to be a fairly late development, with earlier tapered
bricks being hand-trimmed either before or after firing including the rubbed sandstocks of building arched lintels.
Curved chimney brick from Oakleigh Plaster works c 1946 (from David Beauchamp)