In the various positions of
these two switches the current from each individual cell, or from
any adjacent pair of cells, may be used in either direction.
--Contributed by Harold S. Morton, Minneapolis.
** An Optical Illusion [99]
The engraving shows a perfectly straight boxwood rule laid over a
number of turned brass rings of various sizes. Although the effect
in the illustration
[Illustration: An Optical Illusion]
is less pronounced than it was in reality, it will be noticed that
the rule appears to be bent, but sighting along the rule from one
end will show that it is perfectly straight.
The brass rings also appear distorted. The portions on one side of
the rule do not appear to be a continuation of those on the other,
but that they really are can be proved by sighting in the same
manner as before.
--Contributed by Draughtsman, Chicago.
** New Method of Lifting a Table [99]
To perform this feat effectively the little device illustrated
will be required. To make it take a sheet-iron band, A, 3/4 in.
wide and attach a strap to fasten on the forearm between the wrist
and elbow.
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