3. See, that is already something miraculous, considering that on a vertically standing, highly polished surface, not even the lightest down feather can remain hanging without being glued on! How is it possible for the fly without some means of sticking?
4. Some very active natural scientists have found, with the aid of very powerful magnifying devices, that the fly – and all animals of this kind – have a very elastic little bell attached to its feet between the claws, which it uses as tiny vacuums to thin the air, accomplished in the following manner: when a fly places a foot on the upright surface of a window pane, she sucks in the air inside of a bell, thus the foot, provided with the vacuum of the little bell, is held fast to the surface by the weight of the outer air surrounding the little bell.