Wes) 
have already accepted without very carefully testing their validity. 
Often the observations themselves are far from accurate. But the 
essence of scientific method is to observe and describe accurately, 
make careful comparisons, formulate with great caution our guess 
or hypothesis as to the cause of what we observe, entertaining no 
guess that the facts do not justify, and finally rigidly testing our 
hypothesis, ready to reject it if it does not square with other facts, 
and does not enable us to make accurate predictions. 
Disregarding the caution imposed by scientific method and ac- 
cepting the teaching that the earth’s features had resulted from a 
series of “ catastrophes,” rather than from gradual transformation 
by the action of causes still in operation, the geologists, Von Buch 
and de Lue, inferred that the boulders were hurled through the air 
like cannon balls by the force that was supposed to have uplifted 
neighboring mountains. Other writers, like President Dwight, as 
quoted above, enlisted the aid of Noah’s flood. This was the ex- 
planation given by Tomlinson in 1833 to the glacial deposits of 
the Mohawk valley. The flood theory of the drift was also ac- 
cepted at one time by Amos Eaton, professor of botany at ale; 
1864-1895. 
Others pinned their faith to the collision of a comet with the 
earth. Currents, tides, and waves from the north (caused by the 
bursting of hypothetical lakes, the inrush of the ocean, or other- 
wise) won the support of Hayes (1839) and others. The great 
English geologist, Lyell, at one time, and Mather (1843) and 
others in America thought the boulders were transported only by 
icebergs. 
Light from Switzerland 
It seems probable that the honor of first suggesting the correct 
explanation belongs to Perraudin, a chamois-hunter of Switzer- 
land. ‘This unlearned man noticed the huge erratic blocks on the 
Jura mountain crests, and pondered on the manner in which they 
had been carried from a lower to a higher level. He had probably 
never heard of the geologists and their theories, but he had seen 
the valley glaciers of his native land and observed them transport- 
ing boulders. It was “ common sense ” with him to infer the same 
“erratics, ‘This idea he pro- 
agency for the transportation of 
