Mayence surrendered upon capitulation: ye 22nd the Prussians marched in. They endeavoured to persuade the Elector to return, but he was afraid to trust himself among his loyal subjects. Beauharnais had a bloody battle with the army of observation. He was trying to succour Mayence: victory was wavering for some hours, but he did not attain his object, consequently was defeated. We slept at Louisbourg about twelve miles from Stuttgart; the palace and gardens are sumptuous, the Opera house is the largest in Europe. Here in former times Vestris and Noverre tripped upon the light fantastic toe to the admiration and gawky imitation of the clumsy German. To-morrow we shall reach Heidelberg. _1st August, Thursday._--Left Louisbourg at 6 o’clock. Heilbronn, a free Imperial city, very dull, and declining; the Neckar runs by it. Open corn country. I did not visit the Tun, so extolled for its size; I passed a most restless night on account of the myriads of little white bugs. Got to Mannheim at 12. The whole town is animated, a garrison in the town of 6000 men, bodies of troops passing through, couriers coming and going. All too evidently proves the vicinity to the seat of war, but though a _little_ alarming, yet one feels hurried on by an interesting curiosity. The town is beautiful; large stone buildings, fine wide streets, and all the objects cheerful and pleasing. The Gallery contains many fine pictures, some charming _Murillos_; and good Flemish artists have contributed. The Cabinet has some beautiful specimens of mineralogy. At Valenciennes poor Tollemache[86] was killed in the trenches. He is Ly. Bridget’s only son; a spent bomb struck against his bowels and he expired the next day. We go to-morrow to Mayence, which I expect to find a heap of ruins. _Saturday, Mannheim, 3rd August._--I have been reading the _sommation_ and articles of capitulation of Valenciennes. The allies have accorded the garrison in it to return to France but to be considered prisoners of war, with a promise that they will not serve until they have been regularly exchanged for other prisoners.[87] It is very unlikely that they should abide by this convention, and, to say the truth, were I the Government of France they _should not_. Lord Yarmouth told me a _trait_ of French _légèreté_ that amused me. After the D. of York’s _sommation_ there was a parley, during which many people came out of the town. The first intimation the Duke had that the terms were accepted was by the director of the Theatre coming to ask what piece H.R.H. would order the next day. [Sidenote: THE SEAT OF WAR]