One of three entries in a new but not innovative history-of-technology series about old-time inventions, this reinforces the general association of elevators with Otis. Like many of his ilk, Otis gained his fame by improving, producing, and marketing his product. His original invention, demonstrated at the Crystal Palace Exhibition in 1854, was a special safety feature for the steam hoist common in factories of the time. Soon Otis elevators were used for carrying passengers as well as freight, and from there the Otis company went up up up--co-evolving with building construction when masonry buildings gave way to metal-framed skyscrapers; reaching 51 stories in the Woolworth building, where the original 1912 elevators are still in operation; and going up 110 stories (but usually in stages) in the World Trade Center where 20 fulltime mechanics maintain the twin towers' 208 Otis elevators. (Sears Tower, the world's largest building, uses Westinghouse elevators--which can make the trip to the 103rd floor observation deck in 55 seconds.) Automation began in the '2Os; microprocessors introduced in the 1970s respond to calls within ten seconds; and by 1983 we will have elevators that tell us to have a nice day. A smooth ride, though undoubtedly an unnecessary one.