A Little History of Science is just that, a short but nicely done romp through science, with short chapters focused on medicine, physics, chemistry, engineering, and math. I would have liked the content to be a bit more sophisticated and the tone a little less simplistic (it reminded me of junior-high books), and I would have loved to see a timeline showing the relative advances of science over time, but the short chapters are easy to digest, the personal anecdotes funny (did you know that Newton was a pain in the butt? that Darwin was a terrible college student?) and the illustrations evocative, yet simple.
If you want in-depth information, this is not the book for you, I can recommend this book about the history of the periodic table, for instance.