(1)Whenever it appears to the [Central Government] [Substituted by the A.O. 1937, for 'L.G.'.] that it is necessary to impose restrictions upon the use and enjoyment of land in the vicinity of any work of defence or of any site intended to be used or to be acquired for any such work, in order that such land may be kept free from buildings and other obstructions, a declaration shall be made to that effect under the signature of a Secretary to such Government or of some officer duly authorised to certify its orders.
