The Guardians may from Time to Time grant and pay to such of their Workmen and Servants as from Time to Time may be worn out by Length of Service, or disabled or injured in the Execution of their Duties, and to the Proof Master, Wardens, or Officers who sustain Injury from any Explosion at the Birmingham Proof House or at any Branch Proof House of the Guardians, and to the Widows and Families of such Proof Master, Wardens, Officers, Workmen, and Servants, such Sums by way of Superannuation Allowance or Gratuity as the Guardians think fit: Provided that such Sums shall not exceed the Amount of Five hundred Pounds in the aggregate in any One Year: Provided also, that, except as regards Gratuities to Workmen and Servants disabled or injured by Accidents, and to their Widows and Families, the granting of which shall be deemed ordinary Business, the granting of every such Superannuation Allowance or Gratuity shall be deemed extraordinary Business, of which due Notice shall be given.