Doel-taal: Engels
He examines the rate at which sedimentary deposits accumulate. For this purpose, it is sufficient to set up a stick in the sand: little by little, it gets covered with the sand brought by the sea. The accumulation rate of these sediments should not have changed over time. Then the geologist divides the estimated height of the sediments by this rate and he obtains 240 million years. This idea of the Earth experiencing in the past the same natural phenomena that we can observe in the present, will be accepted by the scientific community of the time.