"My invention consists in the application to and combination with vessels of otherwise ordinary construction of a mechanism for driving or thrusting with force and unerring precision a shell or other explosive substance against ships or any other given object, there to explode by contact, substantially as herein described. To accomplish this I fit through the vessel, preferably the bow, a tube having a gate for closing against inflowing water. At the inner end of this tube a stuffing box is used for packing a rod, to which a forward-and backward movement may be imparted to pass in and out of the vessel. To the forward end of the rod an explosive shell is secured, to effect which the gate is first closed to shut out the water. The hand-hole is then opened and the shell introduced through it. The rod is propelled - i.e. It is forced out against the object to be struck or withdrawn there from - by mechanism driven by steam or hand power to suit circumstances."