It was seen in the preceding chapter that it was not until the second half of the XVIIth century that the construction of vessels of war, as such, was begun in Holland. Up to that moment merchant ships were equipped and used for military purposes. In proportion as commerce developed and as dangers from enemies at sea increased, the armament of merchant ships became more and more important. So, personal interest was the cause of partially equipping merchantmen as men of war. It was for this reason that the East India Company built ships which may be considered as types of the kind. Consequently it was just the largest merchant vessels which were most changed as time rolled by. The old types are, therefore, no longer found in this category of vessels; it is among the small craft that they are best preserved. The oldest type of Dutch ship is the “Koggeschip” (Cog) from which are descended the “Krayers” and “Hulken”. These vessels are all clinker built. The “Barges”, “Baertsen”, etc. appeared in the XVth century. Their planking was smooth. They gradually drove out the “Krayers” and “Hulken”, from which they really differed little in form. At the end of the XVth century are found the “Kraak” (carack or galleon) which came to us from the nations of the South, just as we took from them the “Spiegelschip” (a square-sterned vessel) at the close of the XVIth century. The names of “Barges”, etc. now give place to the “Koffen” (koffs) and “Smakken” (smacks); but the old forms do not disappear by reason of this fact; the same types of vessels merely change their name as the result of a few changes in details. It is thus that of the “Tjalken” (tialks), which are not mentioned by Witsen although they existed in his day and were then called “Smalschepen” or “Wijdschepen”. Several other examples of this sort could be given. The likeness of form is even so striking that, at the beginning of the XIXth century, our fleet still showed perfectly the types of Witsen’s time. The changes introduced were merely those of detail. In examining the old types, which are now still in use, it is well not to lose sight of the fact that our ships have, during the XIXth century, increased greatly their length and beam and proportionally also their draught as the result of the improvements of our navigable highways and the digging of new channels. The result of this has been the falling off of certain types, to which the appearance of iron in shipbuilding has also largely contributed. For other types, the improvement of the navigable highways and the creation of ports have brought about their complete disappearance. Thus the construction of the “Bommenhaven” will soon have, as its consequence, the total disappearance of the old “Bommen” of which more will be said further on (fishing boats).