Charles Lyell visited North America four times in the twelve years from 1841 to 1853. Except for the last visit, he both lectured and travelled widely to study geology. In 1841 he opened the second season of Lowell Lectures in Boston, and in early 1842 he gave essentially the same lectures again at Philadelphia and New York. In 1845 and 1852, Lyell lectured only at Boston. In 1853, he returned briefly as a British representative at the New York Industrial Fair. The New York lectures were published verbatim, and Lyell's incomplete notes for his lectures, newspaper accounts, and his wife Mary's correspondence from America provide some insight about the others. During 25 months of travel spanning a dozen years, the Lyells saw more of the United States and southeastern Canada—from the Atlantic coast to the lower Mississippi and Ohio Rivers and from the St. Lawrence Valley to the Gulf Coast—than had most citizens of the New World. After the first two visits, Lyell published two travel journals, which contain much material about American geology, geologists, and general natural history, as well as perceptive commentaries upon most aspects of life in the two young nations. The lectures and journals together provide important insights into the development of geology in America and of Lyell's thinking.
In spite of the fact that Lyell was a poor speaker, the lectures were great successes with the public. American geologists, however, gave more qualified assessments. Major topics covered by the lectures, which reflected the major current issues of the science, included during an eleven-year span: Crustal movements and the earth's interior; Uniformity of processes through geologic time; Coral reefs; Carboniferous conditions and coal formation, as well as the early appearance of land animals; Origin of the drift and the Sinking and submergence of land; Biogeography; and the Uniformity of an organic plan, including negative commentary about progression and transmutation. Lyell's use of examples from both America and abroad gave the subject a cosmopolitan aspect, and his use of many large diagrams was much acclaimed.
Geology was becoming well established in the New World, and Lyell participated in the third annual meeting of the American Association of Geologists and Naturalists in 1842. For field work, he followed his well-honed tactic of seeking experts as guides for efficient learning about local geology and grilling them incessantly. Although initially enthused and open, American geologists soon became apprchensive about Lyell's acquisitiveness for their data. Eventually Lyell's bibliography was enhanced by more than 30 titles on American geology in addition to two travel books, the first of which included a colored geologic map of most of the then United States and adjacent Canada. His other books, Principles of Geology and Elements of Geology, also benefited from countless American examples and from the publication of American editions. Lyell's reputation was enhanced by his American adventures, for, like Darwin and Murchison before, his travels attracted much attention both in the London Geological Society and in the British press. But the visits also enhanced the stature of geology in the New World, and Lyell made several significant original contributions to the understanding of American geology. Moreover, the visits by Charles and Mary Lyell produced a positive impression of America abroad, for they were very captivated by their friendly and industrious hosts and spoke well of them in Britain. On balance, it would seem that the visitors and hosts benefitted about equally.
Simple Empirical Models for Estimating the Increase in the Central Pressure of Tropical Cyclones after Landfall along the Coastline of the United States
