On the Origin of Species the manuscript for his "big book" on Species, "Natural Selection". By mid March 1859 Darwin's abstract had reached the stage where he was thinking of early publication; Lyell suggested the publisher John Murray, and met with him to find if he would be willing to publish. On 28 March Darwin wrote to Lyell asking about progress, and offering to give Murray assurances "that my Book is not more "un"-orthodox, than the subject makes inevitable." He enclosed a draft title sheet proposing "An abstract of an Essay on the Origin of Species and Varieties Through natural selection", with the year shown
Reactions to On the Origin of Species example and Ramsay's data in chapter 9 of "On the Origin of Species" to estimate that erosion of the Weald's layered dome of Lower Cretaceous rocks “must have required 306,662,400 years; or say three hundred million years“. The "necessary corrections" Darwin made to his drafts for the second edition of the "Origin" were based on comments from others, particularly Lyell, and added a caveat suggesting a faster rate of erosion of the Weald: "perhaps it would be safer to allow two or three inches per century, and this would reduce the number of years to one hundred and fifty or