Hello ! I have a Astronomical timing project. The earth's resistance seems to change very precisely every second at 34.7 ohms; or 2083 ohms per minute. I need a circuit or mechanical means to automatically increment this value until T = 12 Hrs. and at that point the resistance decreases linearly until T again = 24 Hrs. The maximum 'trimming' "R" is 3 M ohms. That is the changing quantity over 24 Hrs. The total Earth resistance is roughly 150 M ohms +/- 1.5 percent or about 3 M ohms. The cycle is continuous over 24 hours. Any suggestions welcome! Greetings!