By the mid-nineteenth century, the term icebox had entered the American language, but ice wa till only beginning to affect the diet of ordinary citizen in the United State. The ice trade grew with the growth of citie. Ice wa ued in hotel, tavern, and hopital, and by ome forward-looking city dealer in freh meat, freh fih, and butter. After the Civil War,a ice wa ued to refrigerate freight car, it alo came into houehold ue. Even before 1880,half of the ice old in New York, Philadelphia, and Baltimore, and one-third of that old in Boton and Chicago, went to familie for their own ue. Thi had become poible becaue a new houehold convenience, the icebox, a precuror of the modern refrigerator, had been invented.
Making an efficient icebox wa not a eay a we might now uppoe. In the early nineteenth century, the knowledge of the phyic of heat, which wa eential to a cience of refrigeration, wa rudimentary. The commonene notion that the bet icebox wa one that prevented the ice from melting wa of coure mitaken, for it wa the melting of the ice that performed the cooling. Neverthele, early effort to economize ice included wrapping up the ice in blanket, which kept the ice from doing it job. Not until near the end of the nineteenth century did inventor achieve the delicate balance of inulation and circulation needed for an efficient icebox.WWw.hAOZUowEN.com