Illustrations of the theory and practice of ventilation : with remarks on warming, exclusive lighting, and the communication of sound (1844)
Reid, D. B. (David Boswell), 1805-1863 · London : Longman, Brown, Green, & Longmans · leaf 132
the section. 217. In Fig. 61, a different form of the fanner is represented,the air entering freely on each side of the blades a a throughouttheir whole extent, while the air is discharged by its circumfe- i tk PI VENTILATION BY FANNER. 107 rence throughout its whole extent. Fanners constructed… … *, ^WW/iiiHI Vv 218. If one side of the case within which the blades of the fanner are usually put be unscrewed, and theother be entirely closed (Fig. 63) on turn-ing the fanner, if the number of revolutionsbe considerable, the air, as may be indicatedby the movement induced in smoke producednear…
