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 134
ch was constructed accordingly, and pro-pelled the air forwards or back-wards according as it was worked;but the limited time I had at mydisposal at that period did not per-mit me to have it made so as totest its power with other instru-ments. Within a more recentperiod, a patent has been taken… … 110 WINDMILL-VENTILATOR—PUMP AND BELLOWS. of Belgium, and others, in which two or more threads are used,as they are more equal in their action, and do not occupy somuch space as the single-threaded screw. Fig. 66 shews one ofthe arrangements of this form of screw. THE WINDMILL VENTILATOR. 227. It…
