The railway boom in western Canada ended around 1930. The wave of construction had precipitated the settlement of western Canada, making it possible to transport settlers and goods to the new frontier, and transport the fruits of their labors to consumers, first in eastern Canada, and then around the world. For many people around the world, bread has been a staple of life. So people lived where wheat was grown. But in the 19th century, people in Europe and America began to move to cities, and no longer grew their own grain. Where would the wheat to make bread come from? One place was the new country of Canada. Starting almost 100 years ago, wheat changed Canada. Hundreds of thousands of people settled on the Prairies. Grassland changed into farmland so quickly, the business of growing and exporting wheat experienced a “boom.” Many settlers grew wheat, and some worked for railways that took this valuable crop to be shipped overseas. Towns and cities sprouted along the railway lines. This simple grain was so important it was called “King Wheat.” By 1930, Canada was an important wheat exporter, making a major contribution to feeding the world. The Canadian government established experimental farms and research stations to find better ways of growing wheat. One of the problems was the short growing season on the Prairies. A government researcher named Charles Saunders developed a type of wheat, called Marquis, that took less time to grow. Seager Wheeler, a Saskatchewan farmer, carried on experiments to improve Marquis wheat even more. Another problem was plant disease, which could threaten a successful crop. In 1916, a fungus called “wheat stem rust” devastated the harvest. Dr. Margaret Newton (a plant researcher, not a medical doctor) dedicated her career to developing rust-resistant wheat. Her contributions to agricultural science brought her international acclaim.
有益补充2 （补充1的英文）： At the recent American Geophysical Union meeting in San Francisco, the 25th anniversary of one of the great papers in paleoclimatology was celebrated. The paper, entitled “Variations in the Earth’s orbit: Pacemaker of the Ice Ages,” presented important new evidence supporting the orbital theory of glaciation. Orbital theory goes back over a century but is most closely associated with Milankovitch, who calculated the effects of gravitational perturbations on the seasonal cycle of Earth’s insolation (the radiation incident at the top of the atmosphere). Insolation varies on several time scales, including ~20,000 years (termed precession), ~40,000.
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发表于 2009-12-1 11:07:06
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