"The vestry of any parish or place in the metropolis may allow such compensation as they think just to any engine keeper or other person employed in the service of fire engines who has hitherto been paid out of any rate raiseable in such parish or place, and who is deprived of his employment by or in consequence of the passing of this Act, and any compensation so allowed shall be paid out of the rate out of which the salary of the officer so compensated was payable."