THE STEAMBOAT 2 Sy- 



stem of the boat. Its blades are placed in such a way that 

 as they rotate and push against the water they force the 

 boat ahead. The first steamboat using a screw propeller 

 crossed the Atlantic in 1839. Since that time, there have 

 been many wonderful improvements in the ocean steamship. 

 The first ocean steamers were made of wood. Later iron 

 was used. The first iron steamboat crossed the Atlantic 

 in 1850. About 25 years later, steel took the place of iron, 

 and to-day our great Atlantic steamships are made entirely 

 of steel. 



FIG. 113. A modern steamship. 



Lusitania. Such improvements have been made in the 

 modern trans-Atlantic steamships that they are floating 

 hotels with all the comforts and conveniences that are ob- 

 tainable on land. Some have such conveniences as drawing 

 rooms, smoking rooms, reading and writing rooms, veranda 

 cafes, and even gymnasiums and swimming pools. One 

 of the largest of these, the ill-fated Lusitania, that was sunk 

 by a German submarine, was 790 feet long and 88 feet wide. 

 It was provided with engines of a total horse power of 

 70,000, which gave the steamer a high rate of speed. She 

 held the record for speed, having made 632 knots in 24 

 hours, an average of 26 knots or 30 miles in an hour. She 



