FEW PEOPLE HAVE contributed more technologically to the modern world than Thomas Alva Edison. During a lifetime of more than 80 years, he invented or played a major role in the development of the incandescent light bulb, the phonograph, the telephone, the mimeograph, various types of telegraphy, the motion picture, the radio, the storage battery, and countless other devices. Though all of his inventions would probably have been discovered without him, it is hard not to be awed by the great number and diversity of those which he is in fact associated with. He was without doubt the quintessential inventive genius.

But of course, as with so many other people of genius, not everything about Edison is cause of admiration. He was not, for example, motivated in his endeavors purely by scientific curiosity. "'Anything that won't sell,'" he declared, "'I don't want to invent.'" Nor was his grasp of scientific knowledge profound or even, in some cases, adequate. He did not understand the importance of an AC system of electricity or even Ohm's Law (formulated some 50 years before his time). Many of his ideas and proposals were worthy of a crackpot. He was convinced that balloons and airplanes would never work and that "'ships of the air-yachts, schooners, and brigantines'" should be constructed; that memory consists of sub-particles of matter which come from outer space; and that changing one's clothes produces a chemical reaction in the body that induces insomnia. Nor does Edison's personal conduct inspire respect. He was parsimonious with his employees, pusillanimous with his friends, and predatory with his business associates. As for his family life, Robert Conot, referring to Edison's problems with hearing, sums it up this way: "Edison liked his children, but it was difficult for him to hear them, and he lacked the temperament to spend time on them."

Such glimpses of Edison, given in Robert Conot's splendid biography, A Streak of Luck , present quite a different picture of the inventor than the glorified one current in his own time. Throughout parts of the late 19th and early 20th centuries, Edison was one of the most famous and admired men in the world; people believed that a man who could invent a machine that talks could do anything . Nowadays, however, technological innovation is no longer seen as an absolute good (to put it mildly), and hard times, inevitably, have fallen on inventive genius.Conot's work reflects such modern cynicism and goes out of its way to expose Edison's frailties, both personal and scientific. The debunking, however, though severe is good-humored, and the final effect of Conoths well-researched, enjoyable book is less to shatter the "Edison myth" than to give us a critical appreciation of the man.

This appreciation, Conot recognizes well, cannot be based on Edison's scientific (not to mention personal) accomplishments alone. Edison was in no sense "a great scientist" when measured by the standards of such men as Michael Faraday and James Maxwell (who contributed infinitely more to our understanding of electricity than did Edison). He was, of course, a man of rare intelligence, determination, and good fortune. But what really made for Edison's "genius" was his capacity to bring to fruition the faith of an era. This faith was positivistic; it asserted that there are no limits to the power of human invention, no limits to man's ability to turn ideas into mechanical (and, preferably, commercially viable) products. In Edison's life of frantic ceaseless striving to develop one invention after another-a striving that took place at the cost of most other aspects of his life-this faith is incarnated. As Conot says, "Edison had the ability to make people believe that science was not an absolute, but an infinitely expanding universe, in which to seek was to fine." And of course, he had the ability to make himself believe it also. He would not, otherwise, have accomplished what he did. CAPTION: Picture, Photo of Thomas Edison