Wednesday, 11 April 2018

Sources of Magic Knight Tours: Update

Two minor updates to the list of sources of magic knight tours of the standard chessboard have come to light from my researches in Le Siecle.

Tour 00i by an Unknown composer appears as problem 772 on 25 April 1979 with solution on 2 May 1879. The word puzzle used with it is given as by M. Jacquemin-Molez but the composer of the design is not identified. The column is signed as by A. Feisthamel as usual, but if by him the designer would probably be cited as M. A. F. so I think we have to classify it as still Unknown and from an earlier source. The 1879 date is one or two years earlier than the 1880/81 date given by Murray.

Tour 00f by Palamede (the pseudonym of Count Ligondes) appears as problem 2134 on 31 August 1883 with solution on 7 September 1883. There does not seem to be any mention of its cyclic properties.

Wednesday, 28 March 2018

National Chess Library

Here is a new image of the layout of the bookcases in the ECF Offices at Battle,
with the bookcases numbered 1 to 49.

And a key to the present subject arrangement.

1-2 History, 3-6 Game Collections, 7-10 Openings
11-14 English Periodicals 15 Office Use
16-17 Middle Game 18 Endgame 19 Problems
20 Variants 21-22 Archive

23-25 Introductory Books 26 Office Use
27 Russian 28-30 East European 31 Multilingual
32-34 German 35 Braille 36 Library Catalogues
37-38 West European 39 French
40 Chess Handbooks 41-42 Reference
43 World Championship 44 UK Regional
45 Year Books 46-49 Tournaments.

Monday, 26 February 2018

Magic Square in Figured Tour

In my booklet on Figured Tours published in 1997, there is a knight's tour, A5 on the 8x8 board in which the first nine even numbers form a magic square. The tour is by T. R. Dawson and originally published in Vie Rennaise 19 November 1932. It led me to wonder if the same task could be done on a smaller board of minimum size.

The 3x5 board with a cell added at the middle of each side is of 19 cells, that can be chequered to show 9 dark cells in the form of a diagonal square and 10 light cells. Unfortunately this board has no knight tour, for the same reason as the 3x5 board, formation of a closed path firmed by the knight moves available at b3 and f3.

However if the extra cells are added on the long sides to form a rotary symmetric board as shown below the board becomes tourable. In fact there are 62 symmetric tours. Among these there are just six in which the square formed by the even numbers is magic. As shown here:

I wonder if this result can be new?

Monday, 12 February 2018

National Chess Library

Since September last year I have been travelling weekly by bus to Battle to help with the arrangement of the National Chess Library books on the shelves. The Library is now in the Offices of the English Chess Federation at the Watch Oak. Here is a plan I made of the current arrangement of the subjects on the shelves.

The Library is made up of a number of separate collections, the largest of which are the ECF's own collection and that from Harry Golombek. The books are labelled to show which donor collection they are from, and are now mostly arranged on the shelves by subject rather than collection. Because of the way the Library has accumulated there are many duplicates. Duplicate periodicals are being stored in the loft and duplicate books are on the bottom shelves. The Library is open for visitors, but the offices are closed at week ends.

Sunday, 28 January 2018

Knight's Tour Book Contents

I must try to post something each month at least. New Year's Resolution.
So here is the list of contents of my Knight's Tour Notes book as it now stands.
It is now back to a single book of around 800 pages.

z Theory of Moves 5 Nets, Boards, Moves, Pieces, Freedom, Mobility,
z Theory of Journeys 12 Shortest Path, Angles, 3-, 4-, 6-, 8-Moves, Touring Tests.
z Theory of Magic 24 Magic Arrays, Magic Rectangles, Magic Squares, Step Sidestep.
z Wazir Tours 36 Labyrinths, 6×6, Non-Intersecting, Around the Rocks, Snakes, Figured.
z Knight Move Geometry 53Nets, Triangles, Quadrangles, Polygons, Intersections.
z Symmetry 58 Symmetry, Coding, Generic, Central Angles, Straits and Slants.
z Shaped Boards 68 Octonary 72 Biaxial 80 Birotary 98 Rotary 120 Axial 132 Unary.
z Rectangular Boards 156 Borders, Schwenk Theorem, Symmetries, Oblongs
z Oblong Boards 159 3-rank 180 4-rank, Mediaeval 4×8 202 5-rank  6-, 7-, 8-, up to 24×37.
z Odd Square Boards 217 3×3, The 5×5 Board, 7×7,9×9, 11×11, 13×13, 15×15.
z The 6×6 Board 225 quaternary, binary, angle method, slants, open 3-slant, semimagic
z 6×6 Asymmetric 232 Closed Tours: 4-slant, 6-slant, 8-slant, 10-slant, 12-slant.
z Earliest Knight's Tours 272  Adli. Suli, Mediaeval mss, Aladdin, Nikolai, Nilakantha
z Rediscovery (1725-1825) 275 Euler, Vandermonde, Collini, Warnsdorf, Generation Rules.
z Squares and Diamonds 291 FPH, von Schinnern, Ciccolini, Franz, Wenzelides, Jaenisch
z Roget's Nets 300 Straits & Slants, 3-slant, Reentrant, S&D, Given slants, Max slants
z Pseudotours 309  Simple Linking 311 Octonary 317 Crosspatch 319 Collinian
z Double Halfboard Tours 323 Symmetric Rhombic Halfboard.
z More Squares and Diamonds, 330 Symmetric Rhombic Non-halfboard
z Compartmental 342 Tours from Crosspatches, 346 Enumeration of 8×8 Tours
z Graphic Tours: 348 Directions, Intersections, Circulation 351 Angles Max and Min
z Shapes 359 Triangles, Quadrangles 362 Stars 364 Pictorial 365 Monograms.
z 8×8 Asymmetric Tours 368 Legendre, Rothe, Bilduer, Maximum Asymmetry.
z Near Symmetry 370 Bergholtian, Octonary, Quaternary, Axial, Rotary, Diagonal
z 8×8 Symmetric Tours 382 History 391 Symmetrisation, Given Centre 396 All Centres
z Mixed Quaternary Symmetry 406 h:j:k types: h=1, k=3, h>1 k>3, h=3, j=4, k = 5
z Quaternary Pseudotours, 434 8-fold, 4-fold, 2-fold, 1-fold, Table.
z Tours from QP 489 Aladdin, Vandermond, Non-Crossing, Jaenischian, 493 Other QP.
z Lettered Tours 497 Cryptotours, Alphabetical Tours, Chess Art Here??
z Figured Tours 507 Historical development.
z Magic 8×8 Knight Tours 524 Beverley, Wenzelides, Mysore, Jaenisch, Le Siecle,
z Ligondes 1911, Lehmann 1933, Murray 1936, Marlow 1987, Roberts 2002, Completion 2003.
z Catalogue of the 8×8 Magic Knight Tours 552 Historical, Geometrical, Arithmetical.
z Theory of Magic Knight Tours 578 Existence, Braids, Quartes, Testing Procedure.
z Large Even Square Boards 588 10×10 597 12×12 612 14x14 614 16×16 622 Even Larger
z Leapers 629 Camel. Shaped, Zebra, Zebra-rider,.Giraffe, Antelope, {1,5}, {2,5}, {1,6}, {1,7}.
z King Tours 641 Knots, 2×n  3×n  4×n  5,6×n  7×n, 8×8  Alternating, Figured
z Magic King Tours 655 Magic  Biaxial Diamagic  Axial Diamagic  Larger
z Double-movers 661 2-move R, 2-Move Q, 664 Emperor, Templar, Empress
z 673 Nightrider, Lancelot, Prince, Hospitaller, Night-Commuter
z 675 Caliph?, Gnu, Bison, Fiveleaper, Root-50, Root-65, Root-85.
z Triple-movers 683 3-move R, Hyperwazir 3-Move Q, Pterodactyl,
z Triple Knights WDN, WTN, Centaur, WAN, DFN, TFN,
z Quadruple-movers 692 4-move Magic R Tours, 4-MoveQ, WDTN,
z Multi-movers 704 5-6-MRT, 5+MQT, Raven, Amazon, Wizard.
z Alternative Worlds 722 Non-Crossing Paths 730 Rider Crossovers 731 Hoppers
z New Boards 733 Bent Boards 736 Space Chess, Higher Dimensions, 745 Honeycombs,
z End Notes 751 Bibliography 787 Solutions 790 Glossary 796 Index

The z is a wingding knot symbol that hasn't come out.