sentences:  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.