FORTIFICATION. 147 



of Viviers. A particular species of dungeons were the so called oubliettes, 

 into which prisoners condemned to die of hunger were thrown. One of the 

 best preserved specimens of these is afforded by the tower of Chinon (Jig. 3, 

 in section). The door A leads immediately into the oubliette ; about ten 

 feet above the door are traces of beams, on which, doubtless, was a floor 

 with a trap. The object of the oblique piece C C is not easy to discover. 



m. Fortresses. We shall give here, by a few examples, all the different 

 parts of a fortress or castle-fort in connexion, and for this purpose we select 

 the Old Louvre at Paris, of which/?/. 46, Jig. 11, represents the ground plan. 

 A is a round tower, the donjon standing isolated in the middle of the court. 

 B are drawbridges, leading over the ditches in front of the three gates. 

 C are defensive towers, of which the four at the corners project considerably 

 beyond the face of the wall, that they may better flank the straight lines 

 (curtains). D are the dwellings, which lie in the curtains. E is the castle 

 chapel, and F detached works beyond the ditch. The now destroyed 

 Bastile in Paris, of which Jig. 9 is the ground plan, Jig. 8, a view, and 

 Jig. 10, a section, formed nearly a parallelogram, which was defended by 

 eight towers, A, cylindrical upon conical foundations, flanking the curtains, 

 B, whose battlements and other defensive arrangements we have already 

 mentioned. Over the ditch H leads the drawbridge G to the only entrance 

 of the fortress. The two courts C and D were separated by the middle 

 building, E, which contained the dwelling of the commandant and the 

 barracks. F were guard-rooms, &:c., for the garrison. The towers, vaulted 

 within, were divided into stories, the floors of which were double, to prevent 

 all communication between the stories. Under some of the towers oubliettes 

 were placed. PL 44, Jig. 16, gives a view of the Castle of Rheinstein, 

 belonging to the Prince of Prussia, restored in the spirit of the middle 

 ages. 



A remarkable defensive fortification is the Wall of China, represented in 

 pi. 45, Jig. 1, which is, according to some authorities, 600, according to 

 others, 1200 miles in length, 20 feet high, 25 feet thick at bottom and 10 at 

 top, and erected between China proper and Mongolia and Tungusia as a 

 security against hostile inroads. It passes over mountains, valleys, and rivers, 

 and at regular intervals a tower is erected. Later travellers state that its 

 dimensions as given above are much exaggerated ; that though in some 

 portions well built, in many parts it was little better than a low mud wall, 

 and that it is now in a very dilapidated condition. This wall was commenced 

 247 to 210 years before Christ by the Emperor Tsching- Whang, and con- 

 sisted at first of detached portions, which were united into a whole not earlier 

 than the fifteenth century. 



Modern Times. 



The art of fortification has in modern times made very great advances, 

 the works especially of Erard Bar le Due, Sturm, Rimpler, above all the 

 improvements of Vauban, Cohorn, and later, of Carnot, Virgin, Cormon- 



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