Transportation on Water 



353 



running at top speed, what is the position of the trunk relative to the 

 feet and legs ? Why ? 13. Why is the shifting of a cargo dangerous ? 

 14. What do sailors mean by a " list to port "? 



IV. SAILING A BOAT 



156. Early method of sailing. Sailing a boat into the face 

 of the wind is now so common as to provoke little or no curiosity. 

 In the early centuries of sailing, however, this was considered 

 impossible. The seamen of Phoenicia, Greece, and Rome 

 waited for favorable winds, to carry them, if possible, directly 

 to the desired port. Even triremes might be equipped with sails 

 and delay sailing in order to take advantage of favoring winds. 

 To-day, whether the direction of winds is favorable or not, they 

 are utilized in sailing by skillful adjustment of hull, rudder, and 

 sails, in accordance with certain well-established laws or prin- 

 ciples. Winds cannot be changed by man to suit his wishes ; 

 man must adapt himself and his means to suit the winds and 

 make what use he may of them for his purposes and advantages. 



157. Sailing into the wind. How can a boat sail at an 

 angle of forty-five degrees or more into the face of the wind ? 

 This is, in spite of its 



familiarity, an interesting 

 problem, and its method of 

 solution has a wide applica- 

 tion to other situations. For 

 this reason it is worth special 

 study. It may be well, how- 

 ever, to begin with a com- 

 monplace example, that of 



pushing a Wagon with a FIG. 121. - Showing how a single force 

 Wagon pole, Or a Stick, as m ay have two effects acting in different 



children often do with toy directions - 



express wagons. Although the conditions are different, the 

 fundamental facts are the same in pushing a wagon and in 

 sailing a boat into the wind. 



2A 



