Computers
Ty had an older brother named Otis, who was teaching him about computers. Computers were i...
Before the invention of mechanical refrigeration systems, the only practical method for preventing food spoilage was keeping it cold with ice or snow. In prehistoric times, people would bury extra game and other perishable food in the snow to keep it cold. Later, they dug pits in the ground, lined them with wood and straw, and filled them with snow. The ancient Chinese harvested ice from frozen lakes to use for refrigeration. The "icebox" was the nineteenth-century equivalent of today's refrigerator. It was designed to hold a large chunk of ice and a family's perishable food. The ice had to be replaced daily. Ice was harvested in the winter from frozen lakes and stored in insulated icehouses. By the 1890s, usable natural ice became increasingly scarce in America due to the pollution of lakes and rivers. Iceboxes were cooled by commercially produced blocks of ice until the 1930s, when most Americans began switching to refrigerators.
Ty had an older brother named Otis, who was teaching him about computers. Computers were i...
Every seventy-five years, a bright jet of light races across the Earth's atmosphere. T...
The South American Galapagos archipelago inspired Charles Darwin's theory of evolution...