An intriguing book that does a good job of noting some aspects of the science and technology used in the Civil War. Part 1 looks at three individuals who played important roles in three areas: the mine at Petersburg (aka, the Crater), the Red River dams, and on the Confederate side, creating adequate gunpowder in a technology-lacking society. Part 2 focuses on the technology used under the sea (submarines), in the sky (balloons), and on the wires (telegraph). Ross does a very nice job personalizing the technology of these areas. Three appendices take a closer look at buoyancy (the author is a physics professor) and the history of submarines and balloons pre-dating the Civil War.