THE CARDBOARD CHAIN.
(
Various Dissection Puzzles)
Can you cut this chain out of a piece of cardboard without any join
whatever? Every link is solid; without its having been split and
afterwards joined at any place. It is an interesting old puzzle that I
learnt as a child, but I have no knowledge as to its inventor.
Answer:
The reader will probably feel rewarded for any care and patience that
he may bestow on cutting out the cardboard chain. We will suppose that
he has a piece of cardboard measuring 8 in. by 21/2 in., though the
dimensions are of no importance. Yet if you want a long chain you
must, of course, take a long strip of cardboard. First rule pencil
lines B B and C C, half an inch from the edges, and also the short
perpendicular lines half an inch apart. (See next page.) Rule lines on
the other side in just the same way, and in order that they shall
coincide it is well to prick through the card with a needle the points
where the short lines end. Now take your penknife and split the card
from A A down to B B, and from D D up to C C. Then cut right through
the card along all the short perpendicular lines, and half through the
card along the short portions of B B and C C that are not dotted. Next
turn the card over and cut half through along the short lines on B B
and C C at the places that are immediately beneath the dotted lines on
the upper side. With a little careful separation of the parts with the
penknife, the cardboard may now be divided into two interlacing
ladder-like portions, as shown in Fig. 2; and if you cut away all the
shaded parts you will get the chain, cut solidly out of the cardboard,
without any join, as shown in the illustrations on page 40.
It is an interesting variant of the puzzle to cut out two keys on a
ring--in the same manner without join.