128 NAVIGATION. 



Leith and London, (460 miles,) with two engines, 

 each of 60 horse power, total 120, was the largest 

 belonging to Great Britain. 



The Chancellour Livingstone, at New York, is 

 520 tons, with a high pressure engine of 75 horse 

 power. 



The Lady Sherbrooke on the St. Lawrence is 787 

 tons, with a high pressure engine of 60 horse power. 



The Savannah, in 1819, crossed the Atlantic to 

 Liverpool (about 4000 miles) in 21 days, during 18 

 of which the engine was going, and consumed ten 

 tons of coals per day. 



The St. George, Liverpool to Dublin, 312 ton's, 

 two engines 55 horse power each=110 horse power. 



The St. Patrick, Liverpool to Dublin, 298 tons, 

 two engines 55 horse power each= 110 horse power.* 



On board of a steam boat, a boiler constantly in 

 use, with care, will last from four to five years. The 

 engine usually makes about 29 strokes per minute. 



Ship Building. 



It must be confessed, that as far as the .form of a 

 ship's bottom depends on scientific principles, we 

 have copied our best models from the French, some- 

 times with capricious variations, which more fre- 

 quently turned out to be rather injurious alterations 

 than improvements. 



Copper Bottoms. 



Rodney's fleet in the West Indies, in 1799, had 

 but four coppered ships; but in 1782 the whole Bri- 

 tish navy was coppered. 



* From Leith to London, 495 miles, has been done in calm 

 weather by steam boats in 47 hours. 



