A somewhat different slant on four scientists:- Benjamin Franklin, Thomas Alvah Edison, Joseph Henry (developer of the Smithsonian Institute) and Josiah Willard Gibbs (who made modern practical developments in physical chemistry possible). Presentation of the men and their work from angle of society and economics, in relation to their times. Very English in his assumption of gaps in knowledge, but otherwise interesting in content and viewpoint. Not inspired but more than adequate.