Natural and artificial methods of ventilation.

Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: Natural and artificial methods of ventilation. Source: Wellcome Collection.

    18/96 (page 10)
    —particularly in cold weather, when doors and win- dows are kept closed to exclude draughts—combined with the ascensional movement of the heated air arising from the lungs and body, are also utilised as powerful and never-failing auxiliaries in changing the air and inducing an inward and upward current, even when there is absolutely no perceptible movement of the air outside. “Incessant movement of the air is a law of Nature. We have only to allow the air in our cities and dwellings to take share in this constant change, and ventilation will go on uninterruptedly without our care.”—Parkes. Why a Natural System of Ventilation is Always in Operation. “ Science proves that there is not a moment of time but when there is a movement of the air, and that this 7Jiovement properly utilised is sufficient at all times to change the air in a building and secure ventilationP— Houghton. A scientifically arranged system of natural venti- lation may be described as the application of means by which the natural laws of ventilation can be effec- tively brought into operation, the power which operates in producing the currents and change of air being as constant as gravity. “ Incessant movement of the air is a law of Nature; we have only to allow the air in our cities and dwellings to take share in this constant change, and ventilation will go on uninterruptedly without our care.