a week, and for a cost of less than five dollars. Cost was not the only advantage. The thick walls provided insulation against summer heat and winter cold; the latter was particularly important in light of the dearth of firewood on the plains, which forced the early settlers to burn corncobs, twisted grass, or dried buffalo dung. The walls also withstood prairie winds better than framed walls; even sod houses struck by tornadoes generally survived with no worse damage than the loss of the roof, leaving the walls standing. Sod houses also provided a safe refuge against prairie fires, especially when surrounded by a plowed and back-burned firebreak. The sod house was not without its disadvantages, however. Initially, at least, most had dirt floors, which had to be sprinkled with water to abate dust. To protect against invasion by rodents, insects, and snakes, the interior walls were often shaved smooth and plastered with lime, or with a mixture of local clay and sand or ashes; the lower portions of the exterior walls could also be reinforced, with planks or concrete if they were available, or with a second layer of sod to thicken them. Leaky roofs were also a problem; to protect the inhabitants and the interior furnishings from falling water, dirt, and vermin, it was common to make a ceiling of a white muslin sheet tacked to the walls. Since windows were one of the most expensive elements of a sod house, pioneers on a budget were often forced to make do with windows that were small and few in number; a light muslin ceiling and plastered walls helped to illuminate the house by reflecting daylight through the interior. Sod houses continued to be occupied and built even after wood for construction became available. A number of contemporary photographs show occupied sod houses adjacent to frame barns and outbuildings. The Dowse house was built in 1900, although the Burlington and Missouri River Railroad had reached the nearby town of Comstock in 1899, and a lumber company was available there. During the Great Depression of the 1930s, several Custer County farmers who had lost their homes relocated to vacant land and built sod houses there. As late as 1940, a sod house was built near Dunning, Nebraska. The sod houses of Custer County are particularly well documented, owing to the efforts of Solomon Butcher. An itinerant photographer, Butcher conceived the