Originally chimney pots served an almost purely decorative function. Now pots are used to help with regulating the draught and to help keep birds out of the chimney - especially with a bird guard fitted.

There are many different types of cowls, all serving to help keep rain out, and depending on the nature of the chimney, different types of cowls are used to help increase up-draught and decrease down-draught.

For a fun few minutes exploring all the different kinds of chimney pots in the UK - go to the chimney pot spotter's web site - http://users.iclway.co.uk/yorick/potspot/ .