The treckschuyts preserve an easy intercourse between the most distant parts of the kingdom, and the cheapness of their conveyance places them within the reach of the most slender purse. Every thing relative to these vessels is conducted with such admirable punctuality, that the passenger can tell to the smallest cost in the kingdom what his expenses will amount to, and to a minute when he shall arrive at the end of his journey, in which, if it be long, he carries his provision with him, or purchases a frugal meal at the house where the boat stops a few minutes for that purpose. At those places where the treckschuyts stop on account of the course of the canal being interrupted, and where passengers are in consequence obliged to quit one vessel to go to another, there are females who offer refreshments for sale, consisting of little rolls and small birds, and slices of cold baked eels, fastened to a small stick. The treckschuyts are all under the direction of government, and are truly punctual, convenient, cheap, and agreeable. The town of Delft was about twelve miles, or three hours distant. On the sides of the canal, the surface of the water was frequently covered by the _nymphæa alba_, a magnificent white water-lily, whose expanded and unsullied flowers had a charming effect, particularly when intermixed with _menyanthes nymphoides_, the yellow fringed water-lily, which are very uncommon in England. We passed by several sawing or wood mills, which are moved by wind: the machinery of those buildings, which I afterwards examined, is very curious; they were originally invented by Corneille Van Uitgust. The flies of the mill are fixed to a large beam, which turns on an axis; in the centre of the beam the principal wheel is fixed, which impels one immediately below it, which is also fixed on the middle of a piece of timber, hanging on an axis, to which four perpendicular saws, ten in each compartment, are fastened, which, as the wheel revolves, are elevated and depressed. Two iron hooks are fastened at the end of this beam, which catch a wheel, and as the saw rises and falls, move this wheel one cog; that wheel impels another, which catches into a piece of iron, and draws it towards itself; at the end of this iron there is a cross bar, which presses against the end of the tree, while the other end is sawing, and gradually forces it on to the teeth of the saws, as they proceed in cutting. I remember at Memel, in Polish Prussia, the sawing mills there had another mechanical power, that of drawing up the trees from the barks in which they were brought in the river, into the yard or store-house. I believe mills for sawing timber have been introduced only partially into England. All the mills in Holland rise to a very great height, to secure as much wind at all times as possible. Many of these mills were thatched on the sides as well as the roof.