Countless inventions have been made by man without his having any knowledge of the fact that the machine which in its first idea sprang from a single brain, and was afterwards, during the progress of time, slowly improved and perfected perhaps by many successive generations of inventors, had been in use in nature in a more perfect form than art could accomplish, for ages before man existed on the earth. There is scarcely a principle or part in architecture that has not its natural parallel—walls, floors, towers, doors and hinges, porches, eaves, and windows; thatch, slates, and tiles, girders, ties, and buttresses, bridges, dams, the pyramid, and even mortar, paint, and varnish, are all there. The Eskimo snow-house is an exact copy of the dwelling the seal builds for her tender young; the wasp’s nest is composed of several stories supported on numerous pillars. The well-known instance of the building of the Crystal Palace on a ‘new principle,’ by Sir Joseph Paxton, is mentioned by the author, and is one of the many cases where man has confessedly copied nature in art; for that beautiful structure of iron and glass is simply an adaptation of the framework of the enormous leaves of the Victoria regia plant, which, owing to its formation, combines great strength with great apparent fragility. The present Eddystone lighthouse, which has so long withstood the force of the waves, was constructed in 1760 by Smeaton on an entirely new idea, the model being taken from a tree trunk, and the stones of which it was built being strengthened by being dovetailed into one another, as is the case with the sutures of the skull. The study of the eye of man, as well as of birds, quadrupeds, and insects, has shewn how the most beautiful and gradually improved inventions, such as the telescope, microscope, pseudoscope, stereoscope, multiplying glass, &c., had already been perfected in nature for ages. By the combination of a few prisms and a magnifying glass, is produced that most wonderful of all optical instruments, the spectroscope, which equally reveals to us the constituents of the most distant stars or the colouring matter of the tiniest leaf; and yet the prismatic colours developed by this marvellous instrument have existed equally within the glorious arch of the rainbow and in the tiniest dew-drop as it glitters in the rising sun, ever since the sun first shone and the first rain fell.