536 Puzzles and Curious Problems

410 Answers

last mentioned, that is Saturday, because there are 5217 weeks and only

5 days. It will now be convenient to put the results into tabular form:

January I, 1901-Tuesday.

January I, 200I-Monday. 6 days later (2000, leap year)

January I, 2IOI-Saturday. 5 days later

January I, 220I-Thursday. 5 days later

January I, 2301-Tuesday. 5 days later

January 1, 2401-Monday. 6 days later (2400, leap year)

It will thus be seen that the first days of successive centuries will be Tuesday,
Monday, Saturday, and Thursday-perpetually recurring-so that the first day
of a century can never occur on a Sunday, Wednesday, or a Friday, as I have
stated.

517. THE FLY'S TOUR

Before you join the ends give one end of the ribbon a half-turn, so that there
is a twist in the ring. Then the fly can walk over all the squares without going
over the edge, for we have the curious paradox of a piece of paper with only
one side and one edge!
[Dudeney has described what is now well known as the Moebius strip, one
of the great curiosities of topology.-M. G.]

518. A MUSICAL ENIGMA

The undoubtedly correct solution

to this enigma is BACH. If you turn

the cross round, you get successively

B flat (treble clef), A (tenor clef), C

(alto clef), and B natural (treble

clef). In German B flat is called "B"

and B natural "H," making it read

BACH.

It reminds me of an organ fugue by

B A C H

c. P. Emanuel Bach, based on the

family name and beginning as in the

illustration.