Description of an efficacious Temporary Rudder. 423 
#t ee, and carried through the top blocks at 4A; the end has 
the block r, of a liff tackle purchase, turned in; the other block 
being lashed to one of the stanchions on the ship’s quarter, and 
the fall carried through the leading blocks ss to the steering- 
wheel F, situated upon the ship’s deck. 
A topping-lift, b4, suspends the weight of the rudder from the 
spanker-boom G: it is a gun tackle purchase, and is of great 
use in getting the machine out of the water, and also to assist 
im getting it in; the fall of the ‘purchase is carried along the 
boom to a cleat spiked to it. 
¢ is another topping-lift from the rudder to the mizen-mast 
head ; it likewise assists to get in the machine, as well as for a 
substitute, should either of the guys break ; it should be 3+ inch 
rope. 
Two short luff tackles dd, fixed to the taff-rail and cross 
piece p: they are for the purpose of holding the end of the mast 
firm in the socket, and materially aid“in placing and displacing it. 
A jack-stay, i. This is a rope stretched tight from the planks 
at ee, to the other end of the mast; on this a weight, é, is sus- 
pended. The machine is hallasted sufficiently for common 
occasions when the ship is going less than eight knots; but this 
additional weight, consisting of shot sewed up in canvass, is to 
assist in keeping the whole of the machine in the water, when 
going more than eight knots ; and when going less, to be hauled 
up by the line v. 
The mode of operation in this machine will appear evident 
from the above description: the steering wheel F, being turned 
either way, acts to bring in the fall of one of the guys a, and 
give out the other, producing an inclination of the rudder, as in 
fig. 2, so as to put the ship about as expeditiously as a common 
rudder; and upon the same principle, viz. that of making a re- 
sistance to the ship’s motion, on either side of her keel, at plea 
sure. The ship Cornwall, in which the contrivance was first 
tried, had her wheel fitted close to the rudder-head, and she 
steered with a short tiller abaft the rudder, In ships fitted in 
the common manner, the tackles would Jead to their wheels in 
a similar way; the only alteration from the figure being, that 
the wheel is placed much further forward on the deck, and 
the leading blocks ss, are of course placed opposite to it. 
Certificate and further Observations from Mr. A. Lockwoop, 
Master-Attendant of H. M. Naval Arsenal, Barbadoes. 
The Cornwall lost her rudder on the morning of the 4th of 
January, and got this machine over on the 7th at noon; arrived 
at Barbadoes on the 11th of February, and at Port Royal on the 
23d. During the passage from Barbadoes to Jamaica, this ma- 
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