It would be an interesting thing to make a careful study once a year, towards the end of the summer, of the habits and customs of thunder and lightning. Perhaps in this way we should succeed one day in determining the still mysterious nature of these elusive forces. I, for my part, have been engaged upon the task for many years past. It has produced a big accumulation of records, and in this volume I can find room but for a résumé of them, as varied as possible. - Summary by Camille Flammarion