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.

    345/512 (page 333)
    Cold air always flows to the spot occupied by ■warm air, and dis- places it, because it is hca\-ier. Both are drawn down to the earth, by its attraction, but the heavier cold air with the more force; it tl'erel'ore occupies the lower position, and pushes the warm air upwards. Q. Bi/ tvMch means is a boom better venti- lated—J3j/ opening the upper or lower sash ? A. A room is better ventilated by opening the upper sash; because the hot vitiated air (wliich always ascends towards the ceihng) can escape more easily. Q. Bj/ which means is a hot boom more quickly cooled—By opening the upper or the lower sash ? A. A hot room is cooled more quicMij by opening the loiver sash; because cold au' can enter more freely at the lower part of the room than at the upper. Q. Wliy does wind dbt damp linen ? A. Because dry wind (like a dry sponge) imbibes the particles of vapour from the surface of linen, as fast as they are formed. Q. Wliy is the gallebt of all puUic places HOTTER than the lower parts of the building ? A. B ecause the heated air ascends • and all the cold air /Lwhich can enter