冰箱的起源英語(yǔ)作文
by the mid-nineteenth century, the term "icebox" had entered theamerican language, but ice was still only beginning to affect the dietof ordinary citizens in the united states. the ice trade grew with thegrowth of cities. ice was used in hotels, taverns, and hospitals, andby some forward-looking city dealers in fresh meat, fresh fish, andbutter. after the civil war( 1861-1865),as ice was used to refrigeratefreight cars, it also came into household use.
even before 1880,half ofthe ice sold in new york, philadelphia, and baltimore, and one-third ofthat sold in boston and chicago, went to families for their own use.this had become possible because a new household convenience, theicebox, a precursor of the modern refrigerator, had been invented.
makingan efficient icebox was not as easy as we might now suppose. in theearly nineteenth century, the knowledge of the physics of heat, whichwas essential to a science of refrigeration, was rudimentary. thecommonsense notion that the best icebox was one that prevented the icefrom melting was of course mistaken, for it was the melting of the icethat performed the cooling. nevertheless, early efforts to economizeice included wrapping up the ice in blankets, which kept the ice fromdoing its job. not until near the end of the nineteenth century didinventors achieve the delicate balance of insulation and circulationneeded for an efficient icebox.
but as early as 1803, andingenious maryland farmer, thomas moore, had been on the right track.he owned a farm about twenty miles outside the city of washington, forwhich the village of georgetown was the market center. when he used anicebox of his own design to transport his butter to market, he foundthat customers would pass up the rapidly melting stuff in the tubs ofhis competitors to pay a premium price for his butter, still fresh andhard in neat, one-pound bricks. one advantage of his icebox, mooreexplained, was that farmers would no longer have to travel to market atnight in order to keep their produce cool.
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