. Bulletin - United States National Museum. frame, the operator standing opening the bagswith a cord and closing the mouth alternately with his foot.^* TheHindu bellows is also worked by the heel or thumb of the operatorclosing or opening the inlet. The necessity of a continuous blast more easily manageable musthave been obvious to the workers having the simple bellows. Thefirst steps toward the valve are observed in Africa, where the struc-ture of the bellows is a carved wood frame of Y shape with twobowl-shaped cavities at the ends of the arms. Over the bowls aretied somewhat loosely pieces
. Bulletin - United States National Museum. frame, the operator standing opening the bagswith a cord and closing the mouth alternately with his foot.^* TheHindu bellows is also worked by the heel or thumb of the operatorclosing or opening the inlet. The necessity of a continuous blast more easily manageable musthave been obvious to the workers having the simple bellows. Thefirst steps toward the valve are observed in Africa, where the struc-ture of the bellows is a carved wood frame of Y shape with twobowl-shaped cavities at the ends of the arms. Over the bowls aretied somewhat loosely pieces of skin with the fur side inward. Plung-ing rods are fastened to the apex of the skin bags. On the upstrokethe air is drawn in around the edges of the skin, and on the downstroke the fur is compressed against the edge of the bowl, giving a « W. W. Rockhill. Journey Through Mongolia and Tibet, Smithsonian Institution, Washington, J. Q. Wilkinson. Ancient Egypt, New York, 1879, vol. 2, p, 312. U. S. NATIONAL MUSEUM BULLETIN 139 PL. 6.
Size: 2275px × 1098px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookauthorun, bookcentury1800, bookdecade1870, booksubjectscience
