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THE POPULAR SCIENCE MONTHLY. 



than the eighth of a mile (680 feet) long, of 84 feet beam, and 

 drawing thirty feet of water at load-draught, when the weight of 

 ship and contents amounts to over 25,000 tons. This great vessel 



Fig. 66. The Great Eastern. 



is driven by steam-engines of 10,000 horse-power, turning huge pad- 

 dle-wheels 56 feet in diameter, and a screw-propeller having a diam- 

 eter of 24 feet. 



109. We are evidently fulfilling at least a part of that well-known 

 poetical prophecy which Darwin wrote in the early days of the 

 steam-engine, and possibly before Watt had told him of the great 

 advance which had been produced by his inventive genius : 



" Soon shall thy arm, unconquered steam, afar 

 Drag the slow barge, or drive the rapid car ; 

 Or, on wide-waving wings expanded, bear 

 The flying chariot through the fields of air." 



Note. We are compelled to omit the sketch of the development of the stationary 

 engine, and for it must refer our readers to the publication of which this is an abstract. 

 We shall conclude this series by an abstract of that portion which outlines the Philoso- 

 phy of the Steam-Engine, and exhibits the direction of improvement, and the changes 

 which must precede the production of a possible new type, " the steam-engine of the 

 future." 



1 "Botanic Garden," London, 1781. 



