Lightning Striking Again To the Editor: In reference to Henry Spies "On The House," (1/89) I think that the metal turret should be grounded. Its position as the tallest thing around makes it a lightning rod without a downconductor. Of equal or greater importance is that the downconductor be well grounded. My understanding is that a ground rod driven into dry earth is not adequate; moist earth is required. I am not an expert and became interested only after a 10-foot-high log shed surrounded by 30-foot-high trees was struck and ignited by lightning while my brother and I were inside. The fire was small and easily put out. How did it happen? The trees showed no damage and were not