New 50 pounds note comes into circulation
The new note issued by The Bank of England features the renowned 18th century business partnership of entrepreneur Matthew Boulton and engineer James Watt.
A range of new and enhanced security features have been incorporated into the design of the Boulton and Watt 50 pounds banknote.
These include, for the first time a motion thread, the bank said.
On each note, the green motion thread has five windows along its length, running from the top to the bottom.
The windows contain images of the pound symbol and the number 50.
When the note is tilted from side to side, the images move up and down.
When the note is tilted up and down, the images move from side to side and the number 50 and the pound symbol switch.
The thread is woven into the paper, not printed on it.
The Boulton and Watt banknote marks the first time two portraits have appeared together on the back of a Bank of England note.
Chris Salmon, the bank's chief cashier, said: "The Boulton and Watt” 50 banknote has new and enhanced security features which demonstrate the Bank's commitment to its role of maintaining public confidence in the currency."
The motion thread security feature is one of the new measures which should help members of the public to identify genuine 50 banknotes'.
The Boulton and Watt banknote will initially circulate in tandem with the current 50 pounds banknote featuring Sir John Houblon, the first Governor of the Bank of England, which was introduced in 1994.
The Houblon banknote will remain legal tender until a withdrawal date is set by the bank.