100 YEARS AGO

On the shore of the island of Hadod, latitude 68° 40′ about, in Vesteraalin, north of Lofoten, there was found, probably in the autumn of 1897, a wooden ball, 4½ centimetres in diameter, covered by a thin layer of gum. The ball is of fine workmanship, and just able to float in the water. Circles are engraved upon four parts, and form small rhumbs over the whole surface; and on two places there is engraved with Latin Majuscles the name Melfort. Perhaps some of your readers can say from whence this ball has come. I am writing to the man who has the ball now, to ask him to send it to me.

From Nature 9 November 1899.

50 YEARS AGO

The speed of the meteors is so great that as they rush into the atmosphere of the earth they burn away at heights of about sixty miles. Until recently, the streaks of light produced by the burning meteors provided the only method by which astronomers could study this phenomenon. Such observations are hindered or prevented by cloud and moonlight, and are impossible in daylight. On the other hand, the burning meteor leaves behind it a dense trail of electrons which can reflect radio waves … An important consequence of the radio observations has been the discovery of great meteoric activity in summer day-time. The well-known visual meteor showers … usually last for a few nights. The summer daytime showers detected by the radio method are far more extensive and attain higher rates. The daylight activity, which in May comes from the direction of Pisces, develops rapidly, extending over a wide belt stretching towards the sun, and continues as a great succession of meteor showers until late August. The origin of the streams of meteoric debris is a most important problem of meteor astronomy. It is almost certain that most of them move in orbits around the sun. A few are associated with comets; but it is unlikely that this is the case with all of them. There is difference of opinion as to whether the meteoric debris is all localized in the solar system or whether some comes from interstellar space. The radio observations now being made will help answer these questions. The accurate determination of speeds will resolve the problem as to whether any meteors originate from outside the solar system.

From Nature 12 November 1949.