Carlson, who took charge of Scientific American's longest-running column, "The Amateur Astronomer," in 1995, presents 30 projects adapted from the column's archives-some very detailed, like the one describing how to build a 6-inch reflecting telescope; others mere suggestions, such as the article on Horace Dall's compact telescope which weighed only 8 ounces and could be carried in a vest pocket. The projects include two spectroheliographs for observing the solar disk, a pendulum that detects the earth's rotation, and a method for determining precise geolocation using lunar occultation.