The Evolution of Navigation. 15 



were slowly increased in size and number of rowers until three, 

 four and even five banks of oars, one over the other, were used. 

 They were often from 150 to 175 feet long, and from 18 to 26 

 feet in breadth, drawing from 10 to 12 feet of water and some- 

 times carrying two hundred rowers and several hundred men. 

 All these ships were without decks, whether sailing on the 

 Mediterranean or Atlantic. They sailed by day, putting into 

 harbor at night, and never losing sight of land unless driven by 

 stress of weather. At first they sailed only with the wind, but 

 by slow degrees they learned to tack; then decks were built 

 over the stern and prow, leaving the mid-ships exposed to the 

 high seas. This class of vessels, sometimes with banks of oars, 

 continued until the middle of the last century. In the early 

 part of the fifteenth century smaller but stronger vessels of better 

 material were built for the voyages of discovery undertaken by 

 the Portuguese. At this time also the mariner's compass was 

 brought into general use, having been introduced from Arabia ; 

 eighty years later it found its way to England. Two of the ves- 

 sels of Columbus were decked only at the prow and stern, and 

 the three were manned by one hundred and twenty men. 



The Armada of Queen Elizabeth was formed of merchant vessels 

 fitted up as men-of-Avar, and not until the time of Charles the 

 First were there any regular ships of war in England or, probably, 

 in other countries. 



Commerce Avas usually carried on by companies, with rules 

 regulating the quantity of goods to be exported, so that the 

 market should not be overstocked and unremunerative prices 

 obtained. Sometimes the merchant was owner of the vessel, who 

 adventured with his cargo and sailed in his own ship. The ships 

 were constructed with little reference to speed, sailing forty or 

 fifty miles a day.* 



The steam engine came into use near the middle of the eight-- 

 eenth century in England, and two generations passed before it 

 was used on vessels. The first steamboat ran on the Hudson in 

 1807, in England in 1812. Then another generation passed before 

 the ocean was crossed by the Slriui and Greed Western in 1833. 

 These ships sailed from seven to eight knots an hour. Ten years 

 later iron ships were built ; then came the propeller, the inven- 



"" The breadth was about one-fourth the lenajth, and not until within 

 fortj' years wove the proportions of one-tenth or one-twelfth of the breadth 

 obtained. 



