The east fa�ade, towards Aldersgate Street, is a screen wall, erected in 1831 and executed in Roman cement, with a pediment and four attached Ionic columns standing on a high plinth, with a Venetian window between them.
22.
These outstanding Roman cements are based on the calcic activation of ceramic aggregates ( in Latin " testa ", analogue to our modern metakaolin MK-750 ) and alkali rich volcanic tuffs ( cretoni, zeolitic pozzolan ), respectively with lime.
23.
All the coverings of rough cast, with the ugly plinths of Roman cement, were removed, and a handsome wall facing of stone substituted; the buttresses were rebuilt on solid foundations reaching down to the rock, and good stone plinths added, following as nearly as possible the old lines.
24.
Although the piles were driven to the rock bottom, the water forced its way up, baffling the attempts to fill in between them; this, however, was remedied by using a concrete made of broken stone and Roman cement, which was continually thrown in until the bottom was found to be secure.
