How a gardener suddenly developed into an architect remains to be seen; and, indeed, in this case the architecture was the result of the gardening, or rather, of practical botany applied to art. Some years before the invention of the Crystal Palace, that magnificent plant, the Victoria Regia, had been introduced into England. Its enormous leaves, with their wonderful power of flotation, caused a great stir at the time, and some of my readers may remember a sketch which was engraved in the _Illustrated London News_, and which represented a little girl standing on one of these leaves as it floated on the water. [Illustration: LEAF OF VICTORIA REGIA (REVERSED).] [Illustration: CRYSTAL PALACE.] Mr. Paxton saw how this power was obtained, and the result was that he copied in iron the lines of the vegetable cellular structure which gave such strength to the Victoria Regia leaf, and became more eminent as an architect than he had been as a gardener. The capabilities of the Crystal Palace had lain latent for centuries, but the generalising eye of genius was needed to detect it. A thousand men might have seen the Victoria Regia leaf, and not thought very much of it; but the right man came at the right time, the most wonderful building in the world sprang up like the creation of a fairy dream, and the obscure gardener became Sir Joseph Paxton. I have no doubt that thousands of similar revelations are at present hidden in Nature, awaiting the eye of their revealer. * * * * * NOW we come to the principle of the Buttress, _i.e._ giving support to the exterior, instead of the interior, and strengthening the walls by pushing them together, instead of pulling them together. Putting aside the “flying” buttress, which is simply one buttress mounted on another to support the clerestory walls, the structure of the ordinary buttress is simple enough. The most primitive form of the buttress is often found in country farms, where the farmer sees the walls of his barns and outhouses leaning suspiciously on one side, and, instead of going to the root of things, props them up by a stout pole or beam. This, however, can be nothing but a temporary arrangement, especially as beams have a tendency to rot, and their ends to sink into the earth by the gradual pressure of the wall. The genuine buttress was therefore evolved, the basal part being very thick and heavy, and the upper part comparatively thin and slight. Simple as a buttress looks, much skill is needed in making it, and if it be not rightly built, it does infinitely more harm than good.