Eiffel Tower Wireless Time-Signals.

IT may interest a number of readers of NATURE to know that the Eiffel Tower is at present sending out two additional sets of ``scientific'' time-signals. The scientific signals are arranged as a time-vernier, gaining about one beat in fifty. They have hitherto been sent at 11.30 p.m. G.M.T., followed at 11.45, after the ordinary time-signal is concluded, by numbers which give the moment of the first and the last signal of the set, according to the standard clock of the Observatory of Paris. A comparison can thus be made with the introduction of a very small error, often not exceeding one-fiftieth of a second. These valuable signals have suffered from two awkward features: In summer time they are inconveniently late, and the purring or snoring note (ronfleée) on which they are sent is much obscured by atmospherics when the latter are bad, so that sometimes one failed to pick up the identification breaks which occur at the end of every sixty beats.