“ The council of a county or borough may, at the request of one or more volunteer corps, by agreement hire land on behalf of the volunteer corps for military purposes, for a period not less than twenty-one years, and may contribute towards the expenses incurred by another council in purchasing or hiring land for those purposes, and the expenses of so hiring or contributing may be defrayed in the same manner as expenses of purchasing, and the payment of those expenses, so far as they are in the nature of capital expenses, shall accordingly be a purpose for which the council may borrow. ”