A DISCOURSE 



BOOK III. according to the goodness and choice of the materials, and curiosity in 

 framing, especially roofs and stair-cases, which are of most charges. And 

 here might also something be added concerning the manner of framing the 

 carcases of buildings, as of floors, pitch of roofs, the length of hips and 

 sleepers, together with the names of all those several timbers used in 

 fabrics totally consisting of wood ; but I find it done to my hand, and 

 published some years since, at the end of a late translation of the first 

 book of Palladio ; to which I refer the reader. And to accomplish our 

 artist in timber, with the utmost which that material is capable of, I do 

 recommend him to the study and contemplation of that stupendous roof, 

 which now lies over the renowed Sheldonean theatre at the university 

 of Oxford ; being the sole work and contrivement of my most honoured 

 friend. Sir Christopher Wren, now worthily dignified with the superin- 

 tendency of the Royal Buildings. See Dr. Plot's description of it in his 

 Natural History of Oxfordshire, 272, 273, tab. 13, 14 : also Dr. WaUis 

 de Motu, part. iii. de Vecte, cap. vi, prop. 10. 



Other conversions there are of timber, of all lengths, sizes, and dimen- 

 sions, for arches, bridges, floors, and flat-work, (without the supports of 

 pillars,) tables, cabinets, inlayings, and carvings, screws, &c. with the 

 art of turning, to the height of which divers gentlemen have arrived, 

 and, for their diversion, produced pieces of admirable invention and 

 curiosity : these, I say, belonging to the mechanic uses of timber, might 

 enter here, with a catalogue of innumerable models and other rarities to 

 be found in the repositories and collections of the curious : but let this 

 suffice. 



We did, in book ii. chap. i. mention certain subterranean trees, which 

 Mr. Camden supposes grew altogether under the ground : and truly it 

 did appear a very paradox to me, till I both saw and dihgently examined 

 that piece (plank, stone, or both shall I name it ?) of lignum fossil, taken 

 out of a certain quarry thereof at Aqua Sparta, not far from Rome, and 

 sent to the most incomparably learned Sir George Ent, by that obliging 

 virtuoso cavalier dal Pozzo. He that shall examine the hardness, and 

 feel the ponderousness of it, sinking in water, &c. wiU easily take it for 

 a stone ; but he that shall behold its grain, so exquisitely undulated and 

 varied, together with its colour, manner of hewing, chips, and other most 

 perfect resemblances, will never scruple to pronounce it arrant wood. 



