The technique of dendrochronology, or tree-ring dating, can be used to determine the exact age of timber structures such as mills.
A sample core - like the one shown below - is taken from the oak timbers within a structure. Back at the laboratory, the ring pattern shown on the core is examined and matched with other cores to provide a sequence of dates. These signify the period in which the tree was growing.
The illustrations show Dr Ian Tyers, from Sheffield University, removing a core from the main post of Cromer Windmill near Stevenage, Hertfordshire. The core indicated that the oak tree which forms the post was felled in Spring 1679.
Recently, several mills have been found to be older than previously realised through the use of this technique. Bonwick Associates can assess your mill and arrange a dendrochronological survey to determine the age of its timbers.