Almost a half-century after is completion, the 200-inch Palomar telescope remains an unparalleled combination of vast scale and microscope detail. As huge as the Pantheon of Rome and as heavy as the Statue of Liberty, this magnificent instrument is so precisely built that its seventeen-foot mirror was hand-polished to a tolerance of 2/1,000,000 of an inch. The telescope's construction drove some to the brink of madness, made others fearful that mortals might glimpse heaven, and transfixed an entire nation. Ronald Florence weaves into his account of the creation of "the perfect machine" a stirring chronicle of the birth of Big Science and a poignant rendering of an America mired in the depression yet reaching for the stars.