The Theater of Hydraulic Machines, Volume II

Cap. I. Scoop-wheel with its housing. Tab. II.

...represents the housing, which is built firmly upon a river. That two wheels have been arranged, is intended for the following purpose:

Firstly, because one can often obtain clear and bright water close to the river, which frequently becomes turbid and impure, and such water is more suitable to be led to the place than that which flows in the main stream.

Secondly, because wood, ice, and similar things are often found in the stream, and sometimes even slip through between the ice-stakes and break the paddles of the wheels and boxes; it is therefore better to repair only the paddles (which is easier to do) than the water-boxes, which require much more diligence and accuracy. Also, one can:

Thirdly, use the types of wheels I demonstrated—though only for demonstration—in the first part, Table XIII, Fig. 8, quite effectively; and because there are many boxes, they become that much smaller and shallower.

A B Tab. I. is a stream-wheel. C is the shaft. D is the scoop-wheel with its boxes, in the manner of Ramelli. E are four strong pillars which are well secured and braced below on oak sills F F with struts G. H H are two strong pieces of wood or bearings in which the two journals of the wheel lie. These bearings are made here so that they can be raised and lowered with the wheel by means of two screws, as the height of the water requires. K is the trough into which the lifted water pours, from which it can be carried further through channels and pipes.

That the journal-bearings I, which go on both sides by means of short journals into the grooves a of the pillars E so that they lie firmly and cannot move out, are provided with screws to easily raise and lower such a heavy wheel, seems to be very well done. However, as soon as one sees that such screws cannot remain dry but are constantly subject to moisture, it will immediately be found that it is an unusable contraption. Therefore, it is better to bore holes of a width of 1 to 1 1/2 inches into the pillars E below at e e, and similar ones into the journal-bearings at d d; also, always insert a strong iron bolt into a hole below C as well as into the bearing at d, and raise or lower the bearing by means of a strong iron rod or lever through wedges pushed underneath. One will not have as much expense, and the work will always be in order, which does not work at all with the screws unless they were made of brass (which, however, would be too costly, and in some places too dangerous because of thieves).

Otherwise, when building a scoop-wheel, one must ensure that sufficient force of the water is present, because such a wheel is heavy to move. Specifically, one should not weight it down too much, and it is better that it goes somewhat quickly and in line with the stream than too slowly.

Since such wheels are often drowned by high water, and therefore a whole city must suffer a shortage of water, and since no other type of mechanism can easily be installed due to the size of the streams (as is the case in Bremen on the Weser), I showed in the first part of this Hydraulic, Table XLIII, Figure IV, how one could build a mechanism or pressure-work on a ship. However, how such a wheel—which can be raised and lowered several yards according to high and low water (such as can also be found in Bremen on the Weser at a fulling mill)—[is connected to] the pipes and pistons...