288 



SCIENCE OF HOME AND COMMUNITY 



made the entire voyage across the Atlantic in 4 days, 

 20 hours, and 22 minutes, averaging 28.5 miles per hour. 

 Accommodations were provided for several thousand people. 

 Provisions for d trip across ike ocean. Some idea of the 

 preparations necessary for a trip across the ocean may be 

 obtained from the following figures showing just a few items 

 of food needed by this ship for a round trip : 80 boxes of 

 oranges, 1000 pounds of tea, 1800 pounds of coffee, 10,000 

 pounds of sugar, 210 barrels of flour, 8000 pounds of cereals, 

 3000 gallons of milk, 40,000 eggs, 28 tons of potatoes, 2000 

 chickens, 5500 pounds of butter, 17,000 pounds of mutton, 

 45,000 pounds of beef. This food was cooked in kitchens 

 provided with steam ovens and electric heating devices. 



Steam turbine. In recent years there has been developed 

 a new type of steam engine called the turbine, that is being 



much used on steamships. It 

 is much like a water wheel, 

 which is turned by the force of 

 the water striking against its 

 paddles. In the steam turbine 

 the steam is led through small 

 nozzles and caused to strike 

 against many blades on a re- 

 volving drum. The steam is 

 under enormous pressure, and 

 as it strikes against these blades 

 it causes the drum to revolve 

 at a tremendous speed (figure 114). There are several series 

 of these blades, so arranged that the steam rebounds from 

 one set to the next, the steam being used repeatedly. 



These turbines are now being used on such large steam- 

 ships as the Mauretania, as it is found that they have the 

 following advantages over the ordinary steam engine: 

 (i) There is no vibration, thus allowing the boat to travel 

 smoothly without unpleasant jarring. (2) They occupy 



FIG. 114. Steam turbine with one 

 set of nozzles. 



