Officers and Commissioners of HM Navy, to officers of the yard at Portsmouth, on the advantage of boiling ships timbers in salt water, with copy of letter Bucknell W Polhill to the Navy Board, have received the salt and need instruction on use.

17 June 1768, Officers and Commissioners of HM Navy, to officers of the yard at Portsmouth, ( copy) , on the advantage of boiling ships timbers in salt water, with copy of 17 Oct 1769 Bucknell W Polhill to the Navy Board, have received the salt and need instruction on use, 16 Feb 1769, Navy Board to master shipwright Portsmouth yard on experiment with the Princess Royal, with memo, No report on Princess Royal when docked on 7 November 1786