"The changes I noted were taking place periodically and with such a clear suggestion of number and order that they were not traceable to any cause known to me. I was familiar, of course, with such electrical disturbances as are produced by the sun, Aurora Borealis, and earth currents, and I was as sure as I could be of any fact that these variations were due to none of these causes.
Yo estaba familiarizado, por supuesto, con tales perturbaciones eléctricas como las producidas por el sol, como la Aurora Boreal y las corrientes terrestres, y estaba seguro, como lo podría estar de cualquier hecho, que estas variaciones no se debían a ninguna de estas causas.