When Mrs. Joanna Umiastowska donated in mid-eighties to the Library of the Polish Museum in Rapperswil a marvellous cartographic collection of her late husband, the Museum decided to create a full catalogue of its maps. It had already been in possession of several maps given by Tadeusz Szmitkowski and other occasional donors, whose names remain unknown. Among many other persons who greatly contributed to the development of the Collection of Rapperswil is Jan Nowak Jezioranski, who not only convinced Mr. Roman Umiastowski to bequeath his valuable maps to Rapperswil, but he himself donated some excellent specimens which are exhibited together with Jadwiga and Jan Nowak collection, in the Burghof tenement house, adjacent to the reading room of our Library. Another contributor to the collection was Mr. Adam Heymowski of Stockholm, who frequently presented the Museum with maps of historically Polish territories, which he discovered in Sweden.