13Commutation of Compensation.
The Commissioners of Her Majesty's Treasury may at any Time, on giving Three Months Notice of their Intention so to do, commute annual Payments by way of Compensation for Differential Dues, by paying to the Parties entitled thereto a gross Sum, equal to such Number of Years Purchase as may for the Time being remain unexpired of the Period for which the said Payments are to continue, after deducting Interest on the anticipated Payments at the Rate of Four per Gent.