A district board may concur with any other district board, or with any municipal committee or with any cantonment authority, or with more than one such board, committee or authority, in appointing, out of their respective bodies, a joint committee for any purpose in which they are jointly interested, and for delegating to any such joint committee any power which might be exercised by either or nay of the boards, committees or authorities concerned, and in framing or modifying regulations as to the proceedings of any such joint committee, and as to the conduct of correspondence relating to the purpose for which the joint committee is appointed.