During the pre-Linnaean period, the beauty of insects - especially the Lepidoptera - had attracted a number of collectors; and these "Aurelians" - regarded as harmless lunatics by most of their friends - were the forerunners of the systematic students of later times.
The balloon carries two collectors a given vertical distance apart.
Flame collectors blow out in high winds, whilst water-droppers are apt to get frozen in winter.
The height of the walls in the various observatories, the height of the collectors, and the distance they project from the wall vary largely, and sometimes electrometer, and they sometimes leave hardly a trace on the photographic paper.
2 The notion of the superiority of the palatal bones to all others for purposes of classification has pleased many persons, from the fact that these bones are not unfrequently retained in the dried skins of birds sent home by collectors in foreign countries, and are therefore available for study, while such bones as the sternum and pelvis are rarely preserved.