Two Good Books on the History of Science
Milestones of Science, by Curt Suplee, National Geographic Press, 2000
The size and abundance of illustrations in this National Geographic book may suggest that it is more a coffee-table book than a serious history of science. But by reading through all of the page-length mini-essays, one gets an excellent overview of the entire history of science from the ancient Greeks to the present day, and one learns a little about all of the most important scientists. Because of the format of the book, it doesn't go into much detail on any one topic, and it doesn't say much about overall patterns in the history of ideas.
Landmarks in Western Science: From Prehistory to the Atomic Age, by Peter Whitfield, Routledge Press, 1999
This covers the same basic timespan as Suplee's book, and it is also well illustrated. But it is in many ways a much better book. The chapters are very well written and integrated with the illustrations. Whitfield likes to periodically step back from the mass of historical details in order to make his own integrations, and while some of these are dubious, others are quite impressive and thought-provoking. My only real complaint against Whitfield is the inordinate length of chapter one, on "science" before the Ancient Greeks, which should have been drastically shortened.