Addendum to: “The response of aquifers to periodic forcing”, 18(3), 125–146, 1995

Even though the original paper (Townley, 1995) contained no significant mathematical errors, this Addendum has been prepared (i) to give readers access to 3D graphics that are of much higher quality than are available online, (ii) to provide access to Mathematica notebook files in both .nb and .pdf formats, that demonstrate the use of Mathematica to obtain the six published solutions and to produce high quality graphics and animations to illustrate the solutions, and (iii) to explain and correct a number of minor errors in the original paper, mainly in labelling of axes and curves in Figures.