112 ON THE STEAM BOATS OF 



which had become sanctioned by successful usage, of employing two engines placed upon the 

 wheel guards, a single one has been substituted. This being necessarily placed in the plane 

 of the keel, the rolling of the vessel is rendered more rapid, and more likely to be injurious. 

 It is indeed another well known principle in the stowage of vessels, that the rolling is to be 

 rendered less violent by placing the weights at the greatest possible distance from the plane 

 of the keel, as well as at the greatest height which is consistent with stability. 



The use of a single vertical engine of long stroke is attended with another difficulty, namely, 

 that it requires a large opening to be left in the deck of the vessel, which cannot be suffi- 

 ciently defended from the influx of the sea ; for the bulkheads which surround it, cannot be 

 rendered strong enough to resist a violent wave. 



After all, the main objection to the present model of American steam boats, when con- 

 sidered in their fitness for the navigation of the ocean, is the weakness inherent in the great 

 proportion which their length bears to their breadth and depth. To remedy this defect is not 

 beyond the power of a skilful application of the principles of carpentry. We have already 

 indicated the most obvious method which these principles would suggest, namely, the adoption 

 of the diagonal framing of Seppings, either in the form of trusses, or in the ceiling planks. 



This defect being overcome, no doubt can exist that vessels combining great safety with an 

 average speed of at least twelve nautical miles per hour, can be constructed. Such vessels 

 might make the passage from New York to Liverpool in less than twelve days ; and with 

 such a speed there can be no reason to doubt that they might carry, in the form of coal, more 

 than a sufficient supply of fuel. A direct passage will be absolutely indispensable to success ; 

 for should it be found necessary to make intermediate ports, as for instance, Valentia, or 

 Cork, Halifax, or the Western Islands, the delay consequent on making a harbour, and in taking 

 in fuel, will prevent the passage being performed in a time much less than the average passages 

 of good ships. As the expense of the steam boats will be vastly the greatest, they would not 

 be able to compete with the existing packet ships. On the other hand, in a direct passage 

 performed with the speed of the American steam boats, the saving in time will more than 

 compensate the excess of the daily expense of steam navigation. 



Since the preceding paragraphs were written, an experiment has been made with the British 

 steamer, the 'Great Western,' which renders the successful navigation of the Atlantic, 

 between New York and England, without stopping at an intermediate port, no longer a matter 

 of inference, but a fact established by experience. This vessel has carried more than a suffi- 

 cient supply of coals for the passage ; and although having an average speed of no more than 

 nine nautical miles per hour, has been no more than fifteen days in making her harbour. On 

 examining this vessel, and comparing her performance with that of American steam boats, it is 

 easy to perceive that her speed might be very materially increased without making any 

 important change in her engines, and probably with a saving of fuel. It would be necessary to 

 modify the boilers so as to convert a less quantity of water than they now do into steam, but 

 to furnish it of a tension of 20 or SOffis, instead of 3 L, which they now carry. Nor, when the 

 boiler is of sufficient strength, need any increase of danger be apprehended from using steam 

 of this medium pressure. It is now well established that the mere pressure of the steam is 

 among the least important causes of danger, and that such as are most to be apprehended are 

 as likely to occur in using steam of a single atmosphere as that of ten or twelve. 



The arrival of the ' Great Western ' in New York was preceded by that of the ' Sirius,' 



