Although there was no reliable way of dating periods, there was no shortage of people willing to try. The most well known early attempt was in 1650 when Archbishop James Ussher of the Church of Ireland made a careful study of the Bible and other historical sources and concluded, in a hefty tome called Annals of the Old Testament, that the Earth had been created at midday on October 23, 4004B.C., an assertion that has amused historians and textbook writers ever since.

Although virtually all books find a space for him, there is a striking variability in the details associated with Ussher. Some books say he made his pronouncement in 1650, others in 1654, still others in 1664. Many cite the date of Earth's reputed beginning as October 26. The matter is interestingly surveyed in Stephen Jay Gould's Eight Little Piggies.

There is a persistent myth, incidentally—and one propounded in many serious books—that Ussher's views dominated scientific beliefs well into the nineteenth century, and that it was Lyell who put everyone straight. Stephen Jay Gould, in Time's Arrow, cites as a typical example this sentence from a popular book of the 1980s: "Until Lyell published his book, most thinking people accepted the idea that the earth was young." In fact, no. As Martin J. S. Rudwick puts it, "No geologist of any nationality whose work was taken seriously by other geologists advocated a timescale confined within the limits of a literalistic exegesis of Genesis."

Even the Reverend Buckland, as pious a soul as the nineteenth century produced, noted that nowhere did the Bible suggest that God made Heaven and Earth on the first day, but merely "in the beginning." That beginning, he reasoned, may have lasted "millions upon millions of years." Everyone agreed that the Earth was ancient. The question was simply how ancient.