And with respect to clocks, be it enacted that the commissioners may from time to time provide such clocks as they consider necessary, and cause them to be fixed upon or against any public building, or, with the consent of the owner and occupier, upon or against any private building the situation of which may be convenient for that purpose, and may cause the dials thereof to be lighted at night, and from time to time alter and remove any such clocks to such other like situation as they shall consider expedient.