This was the last exploit of that general. Near this tower there are deposited his remains, over which a mausoleum has been erected. This young commander died of an enlargement of the heart at Wetzlar. His funeral was conducted with uncommon military pomp. The procession moved from the place where he died, across the Rhine to the White Tower, amidst the discharge of cannon, which were fired every quarter of an hour. The trade of the Rhine is here very flourishing, for exclusive of the neighbouring vineyards which produce fine wines, and the basalts of the adjoining mountains used for building and paving, this city derives considerable wealth from the lapis tophaceus or tuf stone, the harder sort of which form excellent millstones; vast quantities are shipped for Holland, to construct or repair its dykes with, and the more friable is used for building, whilst its powder mixed with lime forms the hardest and most durable cement. I saw the cabins of several treckschuyts in Holland covered with it, which were perfectly impervious to the rain: the Germans also use it to floor their houses with. This stone is considered to be a species of the pumice-stone, or imperfect lava, and of volcanic production. On the banks leading to this city, I saw part of one of those amazing floats of timber which are formed of lesser ones, conveyed to this city from the forests adjoining the Rhine, the Moselle, the Maine, &c.; these floats are attached to each other, and form a platform generally of the enormous dimensions of eight hundred feet in length, and one hundred and sixty in breadth, upon which a little village containing about eighty wooden houses is erected for the accommodation of those who are interested in, and assist in navigating this stupendous raft, frequently amounting to seven and eight hundred persons, men, women, and children; besides these buildings, there are stalls for cattle, slaughtering houses, and magazines for provisions: the float is prevented from striking against the shores, where the turnings are abrupt, by the application of thirty or forty anchors, which with the necessary cables are conveyed in fourteen or fifteen boats which precede it, and its course is safely directed by German and Dutch pilots, who are hired for the purpose.