UNCERTAINTY OF SCIENTIFIC THEORIES IN GENERAL.
Another feature which strikes the non-scientific mind curiously is the wide differences among great scientists as to the facts of nature. The age of the earth is variously declared to be ten million years by some, and by others equally able, a thousand million years. The temperature of its interior is stated to be 1,530 degrees by one, and 350,000 degrees by another. Herschel calculated the mountains on the moon to be half a mile high, Ferguson said they were fifteen miles high. The height of the Aurora Borealis is guessed from two and a half to one hundred and sixty miles, and its nature is still more widely described. The delta at the mouth of the Mississippi was calculated by Lyell to have been 100,000 years in forming. Gen. Humphrey, of the United States survey, estimated it at 4,000 years, and M. Beaument at 1,300 years.
The deposits of carbonate of lime on the floor of Kent Cavern in England have been estimated by different scientists to have been from a thousand to a million years in forming.
The discovery of radium and other similar substances, it is said, is almost revolutionizing the theories of the constitution of matter and affecting all physical science.
These facts are not cited to discredit science. No one in his senses would fail to acknowledge our great debt to the earnest and laborious workers in these varying fields. But these instances of many such are cited to show that there is need for caution in accepting proposed theories.