Finally, M. Bouguer (1746) says in his work, p. 83, “that the rudder should make with the prolongation of the keel an angle of about 55° 44´, etc.”. Hence it is incorrect to say that the swing of the rudder could only reach a few degrees. (~Paris~, vol. 4, p. 221.) Furthermore, vessels should be able to come about more quickly in our rivers, with their narrow channels and small depth of water, hence the rudder should be able to swing more than a few degrees. On small inland boats, the rudder is frequently lengthened on reaching shallow water. This elongation was made by means of an isolated board or a movable part (~Van Yk~, p. 221), a thing which happens still very often at the present time. If the tiller can be turned entirely above the bulwarks, which is called in Dutch “geen statie voeren” (without statie), the vessel is said to have a _draai over boord_ in contradistinction to vessels with “statie”. The “statie” means the part of the bulwarks which rises above the tiller[19]. The tiller passes in this case through an opening in the “statie”, which prevents the rudder being brought hard over. The length of the lee-boards is taken at twice the depth of the hold. As many rivers and lakes are lacking in depth, the length of the lee-boards is reduced for inland vessels, in order to prevent them from touching bottom, consequently their width was increased. The lee-boards for the ocean and for the rivers of Zealand are long and narrow. New modifications were made in the rigging of vessels toward the middle of the XVIIIth century. The small bowsprit disappeared in order to make place for the fore-masts which have remained in use since that time. [Sidenote: III 145 etc.] The rigging of the large vessels is sufficiently well known. It is desired merely to dwell on the fact that fore-masts have been placed wrongly on various models of the XVIIth century. A vessel of which the planking is rabbetted into the stem is called a “vaartuig”. The “Aak” (ake) is a boat without a stem and its planking forms a plane up to the bow. The planking ends then at the plane in front. If this occurs for a “Tjalk”, there is obtained what is known as an “Aak Tjalk”. When the after deck is raised so as to come up to the level of the main rail, the vessel is said to be supplied with a “paviljoen”. Thus, for example, a “Statiepaviljoenpoon”, is a “poon” with a raised deck. If the after deck be not raised, the vessel is simply a “Statiepoon”. Vessels can be grouped, then, in the following way: CLASSIFICATION OF SHIPS I. WAR VESSELS. II. MERCHANTMEN. ~A~) For over seas trade; ~B~) For coasting trade and tidal streams. III. FERRIES. IV. BOATS FOR SUNDRY USES AND NOT BELONGING TO THE PRECEDING GROUPS. V. BOATS FREQUENTING THE UPPER PARTS OF RIVERS (BOVENLANDERS). ~A~) For the Rhine; ~B~) For the Meuse; ~C~) For the Upper Rhine and the basin included between the Rhine and the Meuse.