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NOTES ON SAFEGUARDING AND CONSERVING CULTURAL MATERIAL IN THE FIELD                   11.

(v) [[underline]] Dampness. [[/underline]] Partial contact with water; an atmosphere in which the relative humidity is above 60%

(vi) [[underline]] Blast. [[/underline]] Concussion or vibration produced by explosion.

(vii) [[underline]] Mechanical violence. [[/underline]] The fall of an object; the sudden impact of falling or flying material; extreme bending or flexing.

(viii) [[underline]] Abrasion. [[/underline]] Chafing from rubbing or sliding contact with other material.

(ix) Light, usually from the sun.

(x) [[underline]] Darkness. [[/underline]]

(xi) [[underline]] Smoke and dirt, [[/underline]] including carbon from the burning of fuel or other matter; dust carried in the air; greasy deposits from various sources.
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[[footnotes:]] (1)  (Please see page 10.)  The action of atmospheric humidity on objects is not, as a rule, dependent on the actual amount of water vapour in the atmosphere (i.e., on what is known as the [[underline]] absolute [[/underline]], but upon this amount expressed as a percentage of the total amount of water vapour which the air could support when saturated (i.e. at the point when moisture begins to be condensed out and deposited on surrounding objects).  This percentage is known as the [[underline]] relative [[/underline]] humidity.  The significance of this is due to the fact that the capacity of air for absorbing water vapour increases as the temperature rises; so as air gets warmer, if the absolute humidity remains the same, the relative humidity decreases, and the point at which moisture may be deposited from the air becomes more distant.