The biplane designed by Sir Hiram Maxim, which possessed many novel features. Steel and duralumin entered very largely in its construction. It will be noticed that the main 'planes are in three sections, the two outer ones being arched and set at a pronounced dihedral angle. Biplane elevators were mounted fore and aft, carried from the main 'planes by tubular outriggers or spars, which actually extend the whole length of the machine and constitute the main members of the framework of the machine.