The Natural History of Selborne

It has been observed that divers flies, besides their sharp, hooked nails, have also skinny palms or flaps to their feet, whereby they are enabled to stick on glass & other smooth bodies, & to walk on ceilings with their backs downward, by means of the pressure of the atmosphere on those flaps.  The weight of which they easily overcome in cold weather when they are brisk and alert.  But in the decline of the year, this resistance becomes too mighty for their diminished strength; & we see flies labouring along, & lugging their feet in windows as if they stuck fast to the glass, & it is with the utmost difficulty they can draw one foot after another, & disengage their hollow caps from the slippery surface.  Upon the same principle that flies stick, & support themselves, do boys, by way of play, carry heavy weights by only a piece of wet leather at the end of a string clapped close on the surface of a stone.  Tho’ the Virgoloeuse pears always rot before they ripen, & are eatble, yet when baked dry on  a tin, they become an excellent sweet-meat.