To build a folly is essentially to do something a second time, something at an inopportune moment. That something is always the memory of something forgotten, about which we can paradoxically say "There it is again."
Follies were misunderstood, purposeless constructions. They were often only small, extravagant gestures in a garden, easily whisking off the imagination to distant lands, a sort of time capsule built to awaken the memory and induce surprise in passers-by. They marked locations, organized secondary paths in a park, or simply predicted the arrival of better times—a demarcation, a sacred spot, a mysterious trail, a hill whose tragic rocky nature begged for a tower, a party, or the arrival of summer.
“It is demonstrably true that things cannot be other than as they are. For, everything having been made for a purpose, everything is necessarily for the best purpose.” — Professor Pangloss
The virtue of thin sheet metal in giving the greatest glitter for a grain of gold was exploited in the earliest days of metallurgy. However, before the days of rolled sheet and drawn wire, most metal objects were made by hammering and were basically three-dimensional in form.
[In contrast] look at the simple drop press — it’s unmodulated blow striking in a single direction symbolizes much of nineteenth-century mechanized production. To make multiple stampings, stacks of very thin metal sheets were superimposed under the hammer, and the final profile with moderately high relief was gradually achieved as finished sheets were removed from the bottom and new ones added at the top.
When the drop press was used to shape large areas of thin sheet metal, the aesthetic qualities of the surface became divorced from the underlying substance, and decoration became independent of the body needed to support it. In any object there is a natural relationship between the surface and the bulk, that is, between its one-, two-, and three-dimensional aspects. The fakery involved in applying gold or silver playing on a solid copper object is quite different from the deception of an ornately stamped piece of thin sheet brass. Compare a magnificent ormolu furniture fitting or even a gilded plaster picture frame with a cheap lamp base embossed in thin sheet brass. In the former, the surface is simply and honestly applied for its optical effect alone; in the latter the fakery is fundamental for it is dimensionally misleading.