These buildings were not originally designed for this purpose and suffered from various inadequacies, notably insufficient heating in winter.[2] The Museum also functions as a publishing venue, in particular for dozens of books, photo albums, memoirs and brochures devoted to aviation history, including the subject of Polish design and manufacture of aircraft from before the invasion of Poland in 1939 and the post-1945 to the 1960s eras.Among its more popular books are the histories of 16 Polish squadrons in the Royal Air Force (RAF) during the Battle of Britain and the fight for Poland's independence during the First World War.These planes were evacuated during World War II to rescue them from Allied bombing (the museum itself was destroyed in air raids) to German-occupied Poland.In addition, a few Polish pre-war civilian planes were returned by Romania after the war and eventually found their way to the museum.