[27] The elevators are equipped with "legs" or long spouts, within which belts with metal scoops transfer the grain from car to vessel or _vice versa_. The elevators at Buffalo will fill a canal-boat in an hour's time, or load six grain-cars in five minutes. A large whaleback steamship may be relieved of its 200,000 bushels in about three hours. Most of the east-bound wheat of the Middle West is transferred to the seaboard by rail, but that of the northwest, which forms the chief part of the crop, is shipped from Duluth through the St. Marys Falls Canal to Buffalo, where it is transferred to cars or to canal-boats. New York is the leading export market, but Boston, New Orleans, Galveston, Baltimore, and Philadelphia are also important shipping ports. [28] The following is approximately the yield of the chief wheat-growing countries in bushels per acre: Denmark 42 England 29 New Zealand 26 Germany 23.2 Holland & Belgium 21.5 Hungary 18.5 France 19.5 Austria 16.3 Canada 15.5 United States 12.3 Argentina 12.2 Italy 12.1 Australia 10 India 9.2 Russia 8.6 Algeria 7.5 The low average in Australia, India, and Algeria is due mainly to lack of rainfall; in the United States and Russia, mainly to unskilful cultivation. [29] It seems to have been introduced into Turkey from India about the latter part of the fifteenth century, after which it was occasionally heard of in Europe as "Turkey corn." [30] The "tortilla," the national bread of the Mexican, consists of a thick corn-meal paste pressed into thin wafers between the hands, and baked on hot slabs of stone. The corn-meal "mush" of the American, the "polenta" of the Italian, and the "mamaliga" of the Rumanian are all practically corn-meal boiled to a thick paste in water. [31] The gin, invented by Eli Whitney in 1793, enabled one man to do by machinery about the same amount of work as previously had required one hundred laborers. For want of the laws necessary to protect his invention, Whitney was defrauded of the profits arising from it. Neither Congress nor the courts gave him any relief from the numerous infringements, and he died a poor man. [32] The commercial distinction is a sensible one: hair is hard, crisp, straight, and does not felt; wool is soft, curly, and felts readily. [33] An ounce of eggs produces about forty thousand worms, and these, during the grub stage, require about fifteen hundred pounds of leaves, about one-half of which is actually consumed.