In the 18th century, it was unlawful to oppose the government in any way. Supporting the Jacobite cause was akin to treason (the word for murder of a monarch. In Britain today, committing treason is the only crime still punishable by death!) so anyone who openly admitted to being a Jacobite risked imprisonment or execution.
To get round this, supporters of the Jacobites developed secret symbols to privately demonstrate their allegiance to King James. One symbol was the White Cockade, a flower which they would wear in their bonnets or pinned to a sash. Fine glassware crafted to display etchings of these symbols could be used by the wealthy Jacobites to drink a toast to the king or to celebrate the coming of the Prince. One very unusual example of these private tributes to the Prince is the Secret Portrait.
An unidentifiable smear of paint on the surface of a metal tray would not raise any suspicion at all among visiting government officers. But when a cylindrical mirror is placed in the centre of the tray, a perfect likeness of Prince is reflected. This is an old technique known as anomorphic painting. It is thought to have been developed by the Chinese. To the Jacobites it was a very clever method of deception - it allowed them to secretly display a forbidden image in their home.
The symbols of Jacobite support were not just displayed in defiance of the government. They were important for communication between Jacobite supporters. A white cockade worn at a meeting or a symbol sketched at the foot of a letter would let other Jacobites know that they were talking to one of their own. It was like a secret code which would allow them to converse and make plans without the risk of being detected.
