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POPULAR SCIENCE REVIEW. 
in such a manner as to admit of strips of copper, “ Muntz metal,” 
zinc, or other sheathing previously punched, being applied thereto, and 
held thereby. By this arrangement, the strips fixed to the vessel form 
carriers for the sheathing, and obviate the necessity of perforating through 
the ship’s side. The strips are double, that is to say, there is an outer 
and an inner strip, and they are applied to the plates of the vessel by 
means of screws or rivets passing through both strips and into the plates, 
the copper rivets having been previously inserted in an opposite direction 
in the outer strip. The sheets of copper, “ Muntz metal,” zinc, or other 
sheathing, are put on to the projecting copper rivets, with their edges 
overlapping, so that the ends of two sheets are held by one row of rivets, 
and tarred felt, hair, or other similar non-conducting material is inserted 
between the iron plates of the vessel and the copper or other metal 
sheathing. The projecting portions of copper are then hammered so as 
to securely rivet them. 
Sheathing Iron Ships. — Mr. W. R. Mulley , patentee.— In attaching 
metal sheathing to iron ships’ bottoms, caissons, and other like structures, 
according to these improvements, the patentee takes two pieces of angle 
iron with X on one edge. He prefers the iron to be inch thick, angle flange 
j inch wide, and two y flanges together 1 inch, so as to leave about § inch 
in projection on each side. He places them vertically and parallel to 
each other about 18 inches apart on the ship’s side. He then introduces 
a length of say inches wood sheathing between or immediately behind 
the frames, using a portion of their rivets to fasten them on, the grooves 
in the end of which correspond with the projections of the T flange 
formed to receive them. He fastens one of the irons by tapscrews, or 
rivets. He then lays on the ship’s skin, hair and tar, or any other 
suitable composition, puts one end of the wood in its place, then brings 
the other iron against the other end, always with the flange outwards, and 
so on throughout. The ends of the separate pieces of sheathing meet on 
the tops of the irons, and the whole presents a surface as upon a wooden 
ship. He then caulks it and covers it with pitch and felt, so as to render 
it perfectly impervious to water. 
Steering and Manoeuvring Ships. — Messrs. Dunbar & Woodford , 
patentees. — Here the patentees employ an upright shaft or axis at or about 
the centre of a ship or vessel, the lower end of which passes through the 
bottom, and has affixed to it radial blades or vanes which come just below 
the bottom of the ship or vessel, or within a recess formed in the bottom. 
The upright shaft or axis passes within a tubular passage fixed within the 
ship, which rises to a height sufficiently above the water line ; or a suit- 
able stuffing-box or other provision is to be made, in order that no water 
may get into the ship or vessel ; and when desired, the shaft or axis may 
be raised, in order that the vanes or blades may be replaced. The shaft 
or axis is acted on by steam or other power, to give rotary motion thereto, 
in order that the axis or shaft, and the blades or vanes thereon, may be 
caused to rotate towards the right hand or to the left, according to the 
direction in which it is desired that the vessels should be steered. 
Armour Plates. — Messrs. Clapp & Coats , patentees. — In carrying out 
these improvements, the patentees employ plates of iron, or other suitable 
