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THE NATIONAL GEOGRAPHIC MAGAZINE 



verdicts, and what strange laws of nature 

 lend it the power it possesses? 



To begin with, one must remember that 

 light is a matter of vibrations. Accord- 

 ing to the physicists who have developed 

 this wonderful instrument and given it 

 the power to guarantee the sweetness 

 that goes into our coffee cup, a ray of 

 bright light is a matter of five hundred 

 trillion vibrations a second. These come 

 at every angle and hence fill up all the 

 space they reach. If these came at the 

 rate of only one a second, a person would 

 have to live two million years to get as 

 much light in his eye as now comes be- 

 tween the ticks of a clock. 



THE POEARISCOPE'S TASK 



But by a peculiar grouping of lenses 

 and mirrors the scientist is able to strain 

 out all of the crisscross vibrations and 

 use only those which move in a given 

 direction. When these one-direction rays 

 are passed through certain materials they 

 thereby have their direction changed to 

 the right or left. Sugar turns them to 

 the left. 



In most polariscopes used in testing, a 

 strong white light passes through a lens 

 and then to a prism made up of two 

 wedge-shaped pieces of Iceland spar 

 cemented together with a film of Canada 

 balsam. This prism excludes all of the 

 crisscross rays, as a paling fence excludes 

 the passage of all wind-blown straws ex- 

 cept those that present themselves up- 

 right to the openings between the palings. 

 The remaining single-direction rays, or 

 polarized light, pass through the solution 

 which is to be tested and are rotated to 

 the left. They next enter another prism 

 like the first. A pointer attached to 

 thumb-screw is moved as the operator 

 adjusts the prism to correct the rotated 

 rays as they emerge from the sugar solu- 

 tion. 



When the operator looks into the eye- 

 piece at the opposite end from the light. 

 he sees a distinct shadow on the lens, one 

 side being light and the other dark, this 

 being due to the inability of the rays to 

 get through the prism until the "paling" 

 of glass is made perpendicular to the 

 "straw" of light. He turns the thumb- 

 screw until the shadow disappears, and 

 then looks to see where the pointer rests 



on the scale. Its position is the polari- 

 scope's answer to his questions. 



BAGGING THE BIG CROP OF SWEETNESS 



After sugar has come from the centrif- 

 ugals it goes to the bagging-room, where 

 it is put into bags that hold 325 pounds 

 each. These are hauled in trainloads to 

 the docks and shipped to the United 

 States, where the big refineries remove 

 the impurities and transform the sugar 

 from dirty yellow to immaculate white. 



A visit to a big plantation like that at 

 Preston is an impressive experience. It 

 is a small empire within itself, having 

 its own railroad system, its own police 

 department, its own hospital, its own fire 

 department. It covers 280 square miles 

 of territory, possesses a population of 

 nearly ten thousand, and has nearly 

 twelve hundred buildings. Its railroad 

 system has 121 miles of standard-gauge 

 railroad track, 25 standard American 

 locomotives, and nearly 800 railroad cars. 

 About 5,000 oxen are required to haul 

 the cane to the field sidings of the Pres- 

 ton railroad. 



Adjoining it is the Boston plantation, 

 owned by the same company, and to- 

 gether they constitute what is believed to 

 be the largest compact sugar property in 

 the world. 



WHERE TOBACCO RULES 



Sugar is supreme at the eastern end of 

 the island, but tobacco holds the top posi- 

 tion at the western end. Pinar del Rio 

 tobacco soothes the nerves of men of 

 affairs the world over. There are all 

 kinds of tobacco-growers, from the rich 

 "veguero/' with scores of acres of the 

 finest Yuelta Abajo wrapper, grown 

 under cheese-cloth, to the poor thatched- 

 hut dweller, with his little patch that 

 produces nothing but cheap filler. 



Profits in growing tobacco are propor- 

 tionate to the care expended in its culti- 

 vation. The poor denizen of the low 

 country may get $50 out of his acre, 

 while the rich "vega" of the rolling up- 

 land region may bring its owner $5,000 

 an acre. 



The finest tobacco lands in Pinar del 

 Rio are on the south side of the range of 

 mountains that extend through the prov- 

 ince from east to west, midwav between 



