Geoscience Reference
In-Depth Information
many editions, and Elements of Geology that appeared eight years
later. Principles was an immediate bestseller for John Murray its
publisher, who sold 15,000 copies to a receptive audience. It must be
remembered that geology in the 1830s was emerging as an exciting
new science at a time when travel had become possible to a sizeable
portion of the population. Gentlemen as well as others were keen to
embrace geology, many became involved with local and provincial
scientific and literary societies and were anxious to gain a rapid under-
standing of the science. To them, the acquisition of Lyell's works was
therefore of great importance, and Lyell exploited his popularity by
undertaking four lecture tours in North America between 1841 and
1853. These trans-Atlantic sojourns were rewarding in two ways. In
Boston in late 1841 he delivered twelve lectures to an average audience
of 3,000 and received $2,000, equivalent to $30,000 today. He also
recorded the geology of many parts of the eastern North American
continent, observations that he subsequently worked into later
editions of his topics.
As we know, a major stumbling block to geological thinkers was
the Bible, and the limited amount of time that it made available to
produce geological phenomena. Geological events were viewed as
being catastrophic in origin: one-off episodes that were responsible,
for example, for fossils, sedimentation and erosion. By dispensing with
this catastrophism constraint, geologists were able to broaden their
imagination and vision. Suddenly, the volcanic rocks described by
John Strange in northeast Naples and by WilliamRichardson in north-
east Ireland could be seen to be similar in origin to those produced by
contemporary volcanoes such as Vesuvius andMount Etna. Basalt was
not the product of sedimentation from the Noacean Deluge, but was
volcanic in origin, and more importantly could have been erupted at
any time in the past. As was propounded forcefully by Lyell, the past
history of the Earth could be explained by contemporary Earth pro-
cesses: or as he put it 'the present is the key to the past'. This state-
ment became enshrined as the Law of Uniformitarianism, and
remains fundamental to the understanding of the dynamics of Earth
