asked the Financial Secretary to the Treasury how many Government Departments use advertising signs employing a small electric motor driving a windmill which reflects daylight on the sign; and, approximately, how many are in use.

None, to my knowledge.

Would the Minister have a fresh look round? There are quite a few about.

Perhaps the hon. Gentleman will call my attention to them, but I would point out to him that I listened carefully to the answers to the Questions he put to the Minister of Fuel and Power, and I gathered that he dislikes effort to be wasted in inquiries of this kind.