William Hannay was a journeyman of James Wylie of Glasgow in 1791. He was a founder member of the Glasgow Assay Office set up in 1819. His work is recorded between 1794 and 1838. He is the most well know of the Paisley silversmiths.

Prior to 1819 he will have sent his work to Edinburgh for assay, thereafter his items will have the Glasgow marks. More often William Hannay marked his work with Paisley marks, either the Anchor or the Rat/Mouse. Jackson refers to it as a mouse but nowadays it is more often described as a rat. My fanciful inclination is to prefer the "Rat" description, given that Paisley was a port and there will certainly have been pklenty of rats around!