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REVERSE AND CONVERSE CRANK& 2^1
hyperbolae ( 47), the form of which necessarily makes it some- what difficult to realise the motions they represent.
FIG. 209.
The contracted formulae for these mechanisms must, in the first place, make their characteristic property of anti-parallelism clear, we therefore put its symbol between those of the cylinder
\ \
FIG. 210.
fl
pairs. The chain, unfixed, will then be written (C" 2 ' Z 6" 2 '). The reverse anti-parallel cranks will be (C'^C'^f or (C" 2 'zC' 2 ') b , of which formulae we need use only one, let it be the former,
u 2
