This bluff old gate-tower is a bolder specimen of mediæval work than the smaller one at Warkworth. We are lucky indeed to possess a war-bridge which has suffered so little from time and trade and highway officials. If you compare it with the Brangwyn water-colour of Parthenay Bridge, over the Thouet, you will be better able to put the Monnow Bridge in its proper place as a work of defensive art. The French tower is far and away superior: it has scale and dignity: it is a work of architecture as well as an instrument of war. At Monmouth, how different is the technical inspiration! Not a trace of good design saves the gate-tower from being no more than a weapon for ruthless men. A Peace Society could publish the Monnow Bridge as a fact to prove that slaughtering wars have been more vulgar even than the cruel battles of finance. It is the undefensive parts of this bridge that I admire. The ribbed arches are good (p. 93), and in them a slight tentative effort has been made to free the ring of voussoirs from the oscillation sent down through the spandrils when a great weight passes along the footway. “A slight tentative effort,” I repeat, because the archstones have not been made independent from the spandrils. 6. To find arches of this kind we must return to the Pont Valentré at Cahors, which dates from the middle of the thirteenth century. In this noble bridge the voussoirs of all the arches look isolated from the spandrils, as they are rimmed and “extra-dossed.” It was the Romans who invented the “extra-dossed” arch, and they proved that by separating archstones from the spandrils a bridge was relieved from much wear and tear. On the other hand, when archstones are unequal, when they are thicker in their haunches than at the crown, oscillation goes along the full length of a bridge, fatiguing the piers, and causing at times a noticeable shiver, as in the Llanrwst Bridge, designed by Inigo Jones.[121] Even Perronet forgot this effect of repercussion when he built his bridge in the Place de la Concorde at Paris; and ever afterwards he clamped the headers with iron to the interior archstones, as if iron fastened into stone could never become a destructive agent.