Holenderskie księgi sygnałowe w I połowie XVII wieku na przykładzie księgi sygnałowej wiceadmirała Wemmera van Berchem z 1628 roku

The subject of signal books was omitted in Polish science so far, as regards the Dutch navy, as well as english one and others. However, to have a complex outlook on functioning of the navy and a tactic system in these days, it is necessary also to include in research ways of communication, that existed in that time. This article shows rules of communication between Dutch warships in the first half of the 17th century for example of the signal book, that belonged to the vice-admiral Wemmer van Berchem, who commanded a cruiser squadron in 1628 at the North Sea. An additional purpose of that article is to acquaint Polish readers with Dutch signal books, preserved to these days, as well as with usage possibilities and with interpretational difficulties.