These can always be detected by examining them in their backs, as at
Fig. 48; take a small dresser and tap the pipe a few times round ABD
to test for the thickness. Strike it hard enough to just dent it; next
strike the back part of the pipe, E, _with the same force_, and if it
dents much more it is not an equally-made bend. I have seen some of
these much-praised London-made bends that could be easily squeezed
together by the pressure of the thumb and finger. N.B.--Care must be
taken not to reduce or enlarge the size of the bore at the bend.
[Illustration: FIG. 48.]