30 ANNUAL OF SCIENTIFIC DISCOVERY. 



diameter of the paddle-wheels. These alterations sink the hull 18 inches 

 deeper than was originally calculated for, besides presenting a much larger 

 amount of surface tor atmospheric resistance. Her dimensions, as completed, 

 are 222 feet on the load line, 225 feet on deck, 36 feet 10 inches beam, and 

 22 feet hold, or 7 feet deeper than her hull was designed for. The machinery 

 is proportioned as follows ; 



Diameter of cylinder 65 inches. 



Stroke of piston 12 feet. 



Diameter of wheels 33 " 



Length of bucket 7 ft. 9 in. 



Breadth of bucket 22 inches, 



Number of buckets 28 " 



Dip of bucket 4 ft. 9 in. 



She is famished with four single-return flue boilers, two forward and tw"o 

 aft. Both of the forward boilers are 20 feet long, and the after two 22 feet 

 in length. Width of boilers 9 feet 6 inches, and 10 feet 2 inches in height. 

 The entire fire surface is 4,500.44 superficial feet. On the trial trip this 

 steamer (named the Ocean Bird) averaged 17 revolutions a minute with 23 

 Ibs. of steam, running 17 miles an hour against a three-knot tide and a strong 

 head wind, or equal to 20 miles an hour in smooth water. The bow of this 

 vessel possesses great lifting power, causing the waves to pass under the hull 

 instead of being broken by the abrupt termination of the globular line. Her 

 hull is molded to a hollow water-line at both ends, and thus the external 

 pressure is perfectly equalized. 



Novelties in Ship-building. The Cork (Ireland) Reporter thus describes a 

 ship of somewhat novel construction : 



A large ship, with an auxiliary screw propeller, now lies in our harbor, 

 built on a new and curious principle, on which, we believe, she is the first 

 constructed. She is wholly of wrought iron, being framed and put together 

 in the same manner as the Britannia Tubular Bridge, without knees or tim- 

 ber work of any kind in her hull. A plank deck is laid over the iron one, 

 and on this are a couple of large deck houses. Instead of stowing ballast in 

 the usual way, she is provided with water-tight compartments in her huh 1 , 

 into which water can be pumped, for ballast, to any extent required. Her 

 heavy tackle is worked by steam machinery, superseding the necessity for a 

 large amount of manual labor. Owing to the absence of timbers, beams, etc., 

 she has stowage for 900 tons of cargo, though measuring little over 400 tons 

 no inconsiderable advantage in itself. Externally her appearance is very 

 singular, from the convexity of her sides ; in nautical phrase, she " tumbles 

 home" aloft in a most unusual manner. 



For the purpose of facilitating operations in the Black Sea, the British 

 government have recently fitted up two large screw steamers, one as a flour- 

 mill and biscuit-bakery, the other for engineering purposes. This last vessel 

 contains a large workshop between decks, fitted with the best tools obtain- 

 able, consisting of drilling, punching, shearing, shaping, and slotting appara- 

 tus, and two circular-saw benches, besides smiths' forges with fan blasts, and 



