Since the dawn of civilization, people have been curious about Earth's age A. It was not until the nineteenth century that attempts were made to determine the relative geologic age of rocks and fossils. B. Charles Lyell made a good estimate of the Tertiary Period from the fossil record, but his method could not be extended to earlier geological periods. C. Attempts were made to calculate Earth's age from the thickness of surviving sedimentary rock and from the current level of the oceans' salinity. D. In the nineteenth century, scientists made a number of important, but unsuccessful, attempts to calculate Earth's age from the record of various natural processes. E. Darwin and Huxley supported the accuracy of John Joly's Calculation of Earth's age because it agree with their view of how long evolution had been in progress. F. Earth's true age, 4.54 billion years, was determined by combining data from the geological and fossil records.