The Richmond Boulder Trains: Verae Causae in 19th-Century American Geology
In the 1840's and 1850's some of the leading geologists of the day, including Edward Hitchcock, Henry D. and William B. Rogers, Charles Lyell, and Louis Agassiz, investigated long, distinct trains of erratic boulders discovered in 1842 in western Massachusetts. It was hoped that study of the boulder trains would help solve the vexing problem of the origin of the drift. The theories tested by application to the erratics were various in content but remarkably similar in justification. They all appealed to the Newtonian principle of vera causa. This methodological principle appears to have been more fundamental in treating the boulder trains than conceptions drawn from catastrophism and uniformitarianism. Use of the method did not, however, dispel the mystery of the boulders. A clarification of their origins came only with the general adoption of the glacier theory around 1870.