As a verb, the word means to stifle or check; hence damped vibrations or oscillations are those which have been reduced or stopped, instead of being allowed to die out naturally; the "dampers" of the piano are small pieces of feltcovered wood which fall upon the strings and stop their vibrations as the keys are allowed to rise; and the "damper" of a chimney or flue, by restricting the draught, lessens the rate of combustion.
The amount of draft which is necessary to carry out the circulation of the gases and to draw in the adequate amount of air is regulated by dampers placed in the main flue.
All these various changes in the opening of the valves and dampers are automatically performed in the proper order by means of a hand-wheel H, the shaft m resting on the standards t and shaft v.
Further data are provided on basic elements, such as springs, dampers and rigid bodies.
Good practice in the use of the layered treatments and tuned dampers is discussed and illustrated in particular cases.