A fascinating story about the development of the thermometer, which turns out to be much more challenging than just putting a drop of mercury in a glass tube and painting a ruler on it.
This book combines history and philosophy of science in a way that is similar to what I am trying to do on this blog for technology, in which the history grounds and informs the philosophy, and the philosophy guides and interprets the history. Chang discusses a number of problems in thermometry: How do you find something that is always a constant reference temperature to use to set the top and bottom of your scale—and how do you verify this, before you have a thermometer? If different types of thermometers disagree on intermediate temperatures, even after being calibrated against each other at two points, which one is right, and by what standard do we know? How do we measure temperatures far outside the range at which our thermometers can exist or operate as physical objects? How do we identify absolute zero—or even determine whether there is such a thing? In all of this, Chang ties the specific historical problems to much deeper philosophic issues: how we define our concepts, how we establish knowledge, how science can make progress.
I learned a lot of history from this book, and it challenged my ideas in epistemology. Recommended for anyone who enjoys the history or philosophy of science.