Disadvantages... can be entirely removed by... the ridge-dormer. By its use space in the roof, otherwise of little value, becomes the most desirable. Instead of being gloomy, stuffy and hot, the dormers render it perfectly ventilated, light at all times, and cool in hot weather. In frame buildings, it is not so easy, because there must be tie beams... to withstand the thrust of the roof.... Where low stone walls are used... the strength of the walls is sufficient to withstand the thrust...

Small Houses: Their Economic Design and Construction (1922)