Hi, On 31/08/2015 12:14, From HK wrote: > What is a hot water cylinder and how did it play a part in the germination ? Old domestic plumbing features a hot water storage tank (aka cistern, aka cylinder) - often located in an "airing cupboard" where clothes are dried. A place that is constantly warm and hotter than anywhere else in the house. For more detail of the engineering see: http://aphc.co.uk/UNDERSTANDING%20HOT%20WATER%20SY… -- David Pilling http://www.davidpilling.com/