To that end, he quoted some authorities, including Richard Lingenfelter.
Having accomplished that, Morris concluded that the barrel was still in the process of being filled up and that, given the present rate of water coming in and leaking out, the filling process began only 10,000 years ago.
(Strahler, 1987, p.158) Lingenfelter actually attributed the discrepancy between the production and decay rates to possible variations in the earth's magnetic field, a conclusion which would have ruined Morris's argument.
Henry Morris chose not to mention that portion of the paper!
Figure 19.5, curve C, shows the dipole field strength calculated from measurements of magnetism of lava flows and of artifacts such as pottery and bricks, whose age can be determined.