A guide to the scientific knowledge of things familiar / by the Rev. Dr. Brewer.

  • E. Cobham Brewer
Date:
[1863]
Catalogue details

Licence: Public Domain Mark

Credit: A guide to the scientific knowledge of things familiar / by the Rev. Dr. Brewer. Source: Wellcome Collection.

    344/512 (page 332)
    339 DRAUGHT. A. Because the air in the room we occupy is warmer than the air in the hall; therefore, the air from the hall rushes thi'ough the hey-hole into the room, and causes a draught, Q. Will/ is tJiere always a strong draught TTisrBEE tlie door, and through the crevice on each side P A. Because cold air rushes from the hall, to drive the warmer air up the chimney. Q. TT'lig is there always a draught through the WINDOW crevices ? A. Because the external air (being colder than the air of the room we occupy) rushes through the window crevices to drive the warm air up the chimney. Q. Ifyoiv open the lower sash of a window, there is more draught than if yon.open the upper sash. Explain the reason of this. A. If the lower sash be open, cold external air will rush freely into the room, and cause a great draught inwards; but if the up'per sash be open, the heated air of the room will rush out; and (of com'se) there will be less draught inwards.