12THE NORMAL ADVANCEthe span
the parts of this joint play in andout about a foot. A glass, when suddenlyheated, breaks on account of unequal expansion
or if suddenly cooled breaks on accountof unequal contraction. Clocks and watcheslose time in summer, on account of lengthenedpendulum, or of inc...
then the side of the new square =l+a,and it area =(l+a)2=l+2a+a2. The a2 beinginsensible is dropped and leaves the&...