_Lyrids._ Attention was first drawn to the April meteors by Herrick in the United States. Active displays occurred in 1863 and 1884.
η _Aquarids._ Further observations are urgently required of this stream. The radiant is only visible for a short time before sunrise. There is a considerable difference between my results and those secured by Lieut.-Col. Tupman, the discoverer of this system in 1870, whose observations place the radiant at 326½—2½ April 29-May 3. These May Aquarids are interesting from the fact that they present an orbital resemblance to Halley’s Comet, which makes a near approach to the Earth on May 4, twelve days before reaching the descending node.
δ _Aquarids._ The meteoric epoch, July 26-30, was first pointed out by Quetelet many years ago. Biot also found, from the oldest Chinese observations, a general maximum between July 18 and 27 (Humboldt). Showers of Aquarids were remarked by Schmidt, Tupman (1870), and others; but it was not known until my observations in 1878 that the Aquarids formed the special display of the epoch, and that there were many early Perseids visible at the same time.
_Perseids._ Muschenbroeck, in his work on ‘Natural Philosophy,’ printed in 1762, mentions that he observed shooting-stars to be more numerous in August than in the other months of the year. Quetelet, in 1835, was, however, the first to attribute a definite maximum to the 9th-10th. This stream is remarkable for its extended duration, and for the obvious displacement which occurs from night to night in the place of its radiant. It furnishes an annual display of considerable strength, and is, perhaps, the best known system of all.
_Orionids._ Profs. Schmidt and Herschel were the first to discover the Orionids as the most brilliant display of the October period, and accurately determined its radiant in 1863-4-5. Herrick recorded a shower at 99° +26°, Oct. 20-26, 1839, and Zezioli in 1868 recorded many meteors which were ascribed to a radiant at 111° +29°; but there is no doubt that the Orionids were observed in both these cases, though the radiant was badly assigned.
The radiant of the Orionids shows no displacement like that of the Perseids.
_Leonids._ Observed from the earliest times. Humboldt and Bonpland saw it well on the night of November 11-12, 1799, and the phenomenon at its magnificent return on November 12, 1833, was ably discussed by Olmsted. It furnished a splendid shower in 1866, November 13, and many meteors were seen at the few subsequent returns. I observed fairly conspicuous showers of Leonids in 1879 and 1888. There is no doubt the meteors form a complete ellipse, for the earth encounters a few of them at every passage through the node. Grand displays may be expected at the end of this century.
