At the time of the Scientific Revolution in the sixteenth century, and for two centuries after it, most self-made men got their wealth by trade (in which I include the support of trade by insurance and banking), and often by oversea trade. As The Merchant of Venice reminds us, this is how the great fortunes in North Italy, in Holland and in England were made. It was therefore natural that science in these two centuries was agog with problems of trade, and particularly of navigation. The Industrial Revolution in the eighteenth century shifted the source of wealth from trade to manufacture; and manufacture has needed more and more mechanical energy. Science has therefore been preoccupied in the last two centuries with problems which center on energy -- practical problems from the heat engine to the electromagnetic field, and theoretical problems from thermodynamics to atomic structure. Now that we are in sight of having as much energy as we can need, the interest of scientists is moving from the generation of energy to its control, and particularly to the automatic control of power processes, whose tools are the valve, the semi-conductor and the computer. A characteristic invention of the Scientific Revolution was the telescope, of which Galileo heard from Holland, and which he presented to the Doge after a demonstration in the port of Venice in the presence of the Senate in 1609. The characteristic invention of the Industrial Revolution was the power machine which does the routine work of the human muscle. The characteristic invention of the second Industrial Revolution through which we are passing is the control mechanism which does the routine work of the human brain.