The glass in old windows is often the really early 'plate' or 'wide' glass to 'crown' or 'cylinder'.[five] Old glass is recognised by its imperfections ('ream') which lead to optical distortion. Draught proofing for sash windows entails sealing the gaps through which air escapes even though retaining the window’s operation. https://hallajf652xrj1.blogofchange.com/profile