 Complete the following phrase:  Björns survey formed the basis of many subsequent maps of Iceland for the next hundred years; new maps based on new surveys appeared only after World War II. It was an immense work, and Björn realized soon enough that one man alone would not be able to triangulate the whole island in his lifetime, and focussed his attention on the inhabited areas. Yet he managed to survey a good part of the wilderness, too, even if he had to rely on the accounts of the local population in some remote areas. Björn was well aware of the inaccuracies in some regions; already in 1834 he wrote that one should neither have too high or too low expectations of the map, nor trust too greatly nor too little in its usefulness or accuracy. The central highlands were sketchy on his map; they were mapped properly for the first time by Þorvaldur Thoroddsen, whose map was printed in 1901. Still Björns survey is considered a great advancement, especially given the limited resources he had at his disposition. In recognition of his outstanding survey work Björn Gunnlaugsson was awarded the Knights cross of the Order of the Dannebrog in 1846 and also received the Knights cross of the French Légion dhonneur. The map was also exhibited at the Worlds fair at 