Archive for the Crosswords Category

Playfair Again

Posted in Crosswords with tags , , , , on November 8, 2022 by telescoper

It’s been a while since I’ve blogged about my passion for crosswords, but this Sunday’s Azed puzzle in the Observer was in one of my favourite forms so I thought I’d mention it briefly here.

Azed is the pseudonym used by Jonathan Crowther who has been setting the Observer crossword since 1972; this week’s was number 1967. His  puzzles are usually standard cryptic crosswords which, though quite difficult as such things go, are nevertheless set in a fairly straightforward style. Every now and again, however,  he puts together a different type of puzzle that makes a different set of demands on the solver.  To be honest, I don’t always like these “funny” ones, as they sometimes seem to me to be contrived and inelegant, but this last one was a type I really like as it combines the normal cryptic crossword style with another interest of mine, namely codes and codebreaking.

The interesting aspect of this particular puzzle, which is laid out on a normal crossword grid, is that it involves a type of code called a Playfair cipher. In fact, this particular scheme was invented by the scientist Charles Wheatstone whom most physicists will have heard of through “Wheatstone Bridge“. It was, however, subsequently popularized by Lord Playfair, whose name stuck rather than its real inventor’s. Stigler’s Law of Eponymy strikes again!

The Playfair scheme is built around the choice of a code word, which must have the special property that no letter occurs twice within it.  Other than that, and the fact that the more letters in the codeword the better the code, there aren’t any real constraints on the choice. The particular example used by Azed to illustrate how it works is ORANGESTICK.

The codeword is used to construct a Playfair square which is a 5×5 arrangement of letters involving the codeword first and then afterwards the rest of the alphabet not used in the codeword,  in alphabetical order. Obviously, there are 26 letters altogether and the square only holds 25 characters,  so we need to ditch one: the usual choice is to make I stand for both I and J, doing double duty, which rarely causes ambiguity in the deciphering process. The Playfair square formed from ORANGESTICK is thus

This square is then used as the basis of a literal digraph substitution cipher, as follows. To encode a word it must first be split into pairs of letters e.g. CR IT IC AL. Each pair is then seen as forming the diagonally opposite corners of a rectangle within the word square, the other two corner letters being the encoded form. Thus, in the example shown, CR gives SG (not GS, which RC would give).

Where a pair of letters appears in the same row or column in the word square, its encoded form is produced from the letters immediately to the right of or below each respectively. For the last letters in a row or column the first letters in the same row or column become the encoded forms. Thus IC is encoded as CE. When all the pairs are encoded, the word is joined up again, thus CRITICAL is encoded as SGCICEOP.

Obviously, to decipher encrypted text into plain one simply inverts the process as it is completely reversible.

The advantage of this over simpler methods of encipherment is that a given letter in the plain text is not always rendered as the same letter in the encrypted form: that depends on what other letter is next to it in the digraph. That means it isn’t cracked so easily using letter frequencies, as simple subsitution ciphers are.

Now, what does this have to do with a crossword? Well, in a Playfair puzzle like the one I’m talking about a certain number of answers – in the case of the latest Azed puzzle, eight – have to be encrypted before they will fit in the diagram. These “special” clues, however, are to the unencrypted form of the answer words. The codeword is not given, but must be deduced.

What one has to do, therefore, is to solve the clues for the unencrypted words, then solve all the other clues that intersect with them on the grid. Given a sufficient number of digraphs in both plain text and encrypted form one can infer the codeword and hence encrypt the remaining (unchecked) letters for the special answers.

It probably sounds very convoluted, but in this puzzle it isn’t so bad because the “special” clues are relatively straightforward which generates enough “cribs” in the form of letter-pairs in both plain and encrypted form. There aren’t enough pairs to deduce the codeword exactly – as not every letter in the codeword appears among the digraphs – but it helps knowing that it is an actual word rather than a jumble of letters. That, together with the rules for encryption using the  Playfair square, gives enough information to infer the codeword; the digraph PA which encrypts to AE is particularly useful in this case. In this case the codeword has 14 letters. I won’t tell you what it is because the competition is not yet closed!

What has to be done then is to use the codeword to complete the unchecked letters in the specials in their encrypted form. That bit is relatively straightforward but for the competition one also has to supply a “normal” cryptic clue for 9 down. That’s always the bit I find hardest!



A Second in Azed!

Posted in Biographical, Crosswords, Uncategorized with tags , on June 26, 2022 by telescoper

I was more than a little surprised this morning to find that I had won Second Prize in the latest Azed Crossword Competition in the Observer newspaper. This only the third time I’ve been among the medals (so to speak); I got a First Prize last year and a Third Prize exactly 11 years ago today.

As I’ve mentioned before, the monthly Azed Competition puzzle involves not only solving the Azed crossword but also supplying a cryptic clue for a word or phrase given only as a definition in the crossword. This competition is tough, partly because Azed is a stickler for syntactical soundness in submitted clues, and partly because many of the competitors are professional crossword setters. I’ve struggled recently to find the time and the energy to make a decent attempt at the Azed competition, but this competition puzzle was published on the last Bank Holiday Weekend so I had more time than usual to think about it. The target word was PEANUTS and my clue was

Source of allergic upset gripping one’s interior? Possibly!

Usually in a cryptic crossword clue one part of the clue provides a definition of the answer and the other a cryptic allusion to it; the solver has to identify each part. This clue is of a slightly different type called “&lit” which means that two different readings of the clue give you the definition and the cryptic allusion. The cryptic reading gives A (source of Allergic) in an anagram of UPSET containing N (oNe’s interior) indicated by the word “possibly”. UPSET is often used as a anagram indicator but not in this case. The surface reading of the clue also suggests PEANUTS.

P.S. I think the First Prize clue was very good indeed so congratulations to K. Bolton!


Eightsome Reels Again

Posted in Crosswords with tags , , on June 19, 2022 by telescoper

I haven’t blogged about crosswords for a while so I thought I’d mention this week’s Azed puzzle (No. 2610) which is of ‘Eightsome Reels’ type, as explained in the picture above. I mentioned a similar one years and years ago (Azed No. 1921) so I thought I’d make a few comments on this one. I won’t give the full solution though because that would spoil the competition but I will give a hint or two.

The solutions are obviously all 8 letters long and they have to be fitted in the squares surrounding the corresponding number. The trouble is that you’re not told which square to start from, or whether the letters are to be entered clockwise or anticlockwise.

The only way I know to start one of these puzzles is to solve several adjacent clues without entering them in the diagram and then see if I can find a way to fit them together on a bit of scrap paper. The structure of the diagram guarantees many checked letters (i.e. overlaps) between neighbouring answers so once you have a few then the subsequent ones get easier to fit in. These puzzles are usually difficult to start though.

In this particular case I managed to solve about half the clues before entering anything on the grid. But how to write them in so they fit together?

For me the solution was to get the three answers in the corner at the bottom right corner (35, 36 and 30). I think 35 is a nice clue:

35. Erica, breaking rule? – ‘a thing of shreds and patches’

Think American novelist following by an anagram; the reference to Gilbert & Sullivan gives you JONGLEUR (a wandering minstrel). The following clue is the easiest of the lot

36. How corpse ends in morgue’s awfully … so?

This is clearly GRUESOME (end of corpse, i.e. E in anagram of MORGUES).

Now you see that EUR and RUE are common to the two answers so they must fit in the three lights running vertically upwards between 35 and 36 and the two words must be ordered differently so that one is clockwise and the other anti-clockwise. If you write RUE upwards here (so GRUESOME is clockwise), then the three letters in the corner will be MEG. If on the other hand you write them downwards (so GRUESOME is anticlockwise) then the three letters in the corner are SOM. The rubric states that the unchecked letters in the corners can be arranged to form LESS FINE POEM which does not contain a G. Thus the first possibility is excluded. The answer to 36 must therefore be written anticlockwise and the answer to 35 clockwise to mesh with it.

To check this is right you can solve 30, the answer to which has three letters in common with GRUESOME and must be written clockwise.

The symmetry having thus been broken, all you have to do is solve the other clues and fit them in accordingly…

From Labour to Labor

Posted in Crosswords, History, Politics with tags , , , , , , , , on May 22, 2022 by telescoper

I don’t know very much about Australian politics but I was delighted yesterday to hear news of Rupert Murdoch’s defeat in the Federal elections. The losing leader of the illiberal party, and previous PM, Scott Morrison, has now resigned. I’ve got nothing against Mr Morrison’s family, but I’m glad he’s going to be spending more time with them.

One thing that confused me is that the victorious Australian Labor Party is the spelling of the word “Labor”. I think Australians use the English spelling “labour” for the noun or verb so why the political party uses a different spelling for the political party is unclear to me. It is however just a name, and we all know that a rose by any other name would smell as sweet.

Some people refer to “labor” as the American spelling but it’s not as simple as that. The English word “labour” is derived from the 3rd declension Latin noun labor/laboris from which in turn is derived the verb laborare. The same sort of Latin origin is the case for many other familiar words: honor, color, valor, humor, vapor, rigor, and so on. All these were original Latin nouns that came into English via Norman French in the course of which they acquired the “u”.

The person responsible for the spelling of these words in American English (ie “labor” etc) was Noah Webster who thought English spelling was unnecessarily complicated and reverted to the Latin in these cases. It was also he who turned “centre” into “center”, for example. This spelling was introduced in his famous dictionary, first published in 1828, and subsequently acquired by the G&C Merriam Co and still in circulation nowadays after many revisions as the Merriam-Webster Dictionary.

Anyway, my point is that the English often look down on such spellings as “labour” and “colour” as vulgar Americanism but these are the “original” (unfrenchified) spellings.

It’s interesting that Norman French words sometimes displaced Old English words entirely but sometimes the Old English form survives as synonym. For example, the Old English word for “colour” is “hew” which survives as the English “hue”. The Old English word for “labour” is “swink” which has completely disappeared from common usage (though it is listed in the One True Chambers Dictionary with the description archaic).

All of which nonsense gives me an excuse to mention that I managed to get an HC (“Highly Commended”) for my clue in Azed Competition No. 2603 which I thought was a very tough puzzle to complete, which is no doubt why there were only 117 entries!

50 Years of Azed

Posted in Biographical, Crosswords, Maynooth on March 6, 2022 by telescoper

Just a very quick post to mark the fact that it was on Sunday 5th March 1972 that the first Azed Crossword set by Jonathan Crowther was published in the Observer. Today’s special 50th anniversary competition puzzle “Looking Back” is No. 2595. I have been too busy recently to spend much time on competition entries – I didn’t have time to look at last month’s puzzle at all – but I did buy the Observer today because it’s a special occasion and hope to have a bash at the puzzle sometime in the week.

There’s a piece about the 50 years of Azed dated a few days ago here.

Incidentally, I noticed that the Everyman Crossword competition in the Observer is now accepting postal entries again so I may send in an entry for the first time in over two years.

Another thing I noticed is that there is a lunch to commemorate Azed’s 50th anniversary at Wolfson College, Oxford on 28th May. The timing is a bit tricky because of University examinations here in Maynooth but I’ll see if I can manage to go. The Azed 2500 lunch planned for 2020 was cancelled owing to Covid-19 restrictions, but I attended the Azed 2000 lunch in 2010 and enjoyed it enormously. On that occasion, though, I only had to travel to Oxford from Cardiff!

Carte Blanche

Posted in Biographical, Crosswords on February 6, 2022 by telescoper

After spending this afternoon going through lots of papers in an attempt to work out how soon I’ll be able to retire – answer: not soon enough – I’ve only just realized that today there is an Azed Competition Prize Puzzle (usually the first Sunday of every month). I haven’t got the energy to do it now, but will have a go later in the week if I get the time.

Some years ago at a lunch event I had the opportunity to chat with some professional crossword compilers. It seems one gets paid around £150 (give or take) for setting a crossword in a national newspaper, which isn’t a lot considering how difficult it is. It has crossed my mind a number of times that I might try to supplement my retirement income that way.

However, when I saw today’s Azed puzzle (which is ofa special Carte Blanche form) I suddenly hit on a potentially lucrative idea.
I’ve decided to start a crossword competition of my own. Here  is Telescoper Prize Crossword No. 1.

Instructions for solvers. To enter the competition, devise a set of clues and solutions that fill the above grid in the manner of a typical Azed puzzle. Mail completed grids, together with clues to me at:  Telescoper Prize Crossword No. 1, PO Box 16  (across), Maynooth, Ireland. The best entries, as judged by me, will win 27p in (used) postage stamps plus the chance to see their crossword in a national newspaper with my name as setter.

As a business plan, this simply can’t fail. It’s nearly as good as running an academic journal!

The Omicron Variant

Posted in Covid-19, Crosswords, mathematics on November 30, 2021 by telescoper

As a theoretical physicist I use Greek characters all the time in mathematical work but, being very slow on the uptake, I only just realized a few days ago that the name of the Greek letter ‘omicron’ (ο) is derived from the Greek meaning ‘little-o’ while the name ‘omega’ means ‘big o’.

More recently still a Greek friend of mine pointed out that the lower-case symbol for omega (ω) was originally formed as ‘oo’, i.e. double-o.

In modern Greek ο and ω are pronounced the same but in ancient Greek the vocalisation of ω was longer than that of ο, suggesting that οmicron is more like short ‘o’ than little ‘o’ while omega is long `o’ rather than big ‘o’.

Incidentally, I was brought up to pronounce π like “pie” but in most of Europe (including Greece) it is pronounced “pee”. It is in fact the Greek letter ‘p’. I feel I’ve been delta very weak hand when it comes to Greek pronunciation and I’ll beta majority of theoretical physicists feel the same. I think we need to take a nu approach in schools, and rho back from the old ways. Anyway I’m going home now to eta bit of curry for supper…

The Affair of the Missing Trophy

Posted in Covid-19, Crosswords with tags , , on May 13, 2021 by telescoper

A few weeks ago I posted about my first ever First Prize in the Azed Crossword Competition. At the end of that post I mentioned that I was eagerly anticipating being sent a silver trophy called the Azed Instant Victor Verborum Cup to hold for a month before passing it on to the winner of the next competition.

Unfortunately it seems that, owing to a combination of the Royal Mail and Covid-19, the Azed trophy has gone missing somewhere on its travels. In fact it hasn’t even reached the winner before me (a Dr S.J. Shaw) yet. The chances of it being located, retrieved and then sent to me before it would be time to send it on to the next winner are now remote so I don’t suppose I’ll ever get my hands on it. Ho hum.

Still, I did get a nice card from Dr Shaw explaining the situation and sending his congratulations:

I hope the trophy is found because it would be a shame if the tradition of passing it on came to an end, but it’s not such a big deal that I’ll miss out on having it on my mantelpiece for a few weeks. At least it absolves me of the responsibility of ensuring it reaches the next winner…

A First in Azed

Posted in Biographical, Crosswords with tags , , , , on April 25, 2021 by telescoper

I was roused from my Sunday-morning lie-in by the news that I had actually won First Prize in the latest Azed Competition. The best I’ve done previously was third place, and that was almost a decade ago!

As I’ve mentioned before, the monthly Azed Competition puzzle involves not only solving the Azed crossword but also supplying a cryptic clue for a word or phrase given only as a definition in the crossword. This competition is tough, partly because Azed is a stickler for syntactical soundness in submitted clues, and partly because many of the competitors are professional crossword setters.

I’ve struggled this year to find the time and the energy to make a decent attempt at the Azed competition, but the latest competition puzzle was published on Easter Sunday so I had Easter Monday to think about it. Solving the actual puzzle wasn’t too hard this time, which gave me plenty of time to work on the harder bit of composing a clue.

The target word was FILATORY (a machine for spinning thread). For some reason the first thing that popped into my mind was Greek Mythology, specifically the Moirai (Fates) who between them weave the tapestry of life, but one of whom, Clotho, spins the thread. I noticed that one can find the letters of TRIO in FILATORY leaving FAY+L. I looked up FAY in the One True Chambers Dictionary where I found that in its meaning as “fairy” is is derived from the Latin Fata. Even better. I just need to find a way of putting an L into the mix but as a standard abbreviation for “line” that wasn’t too hard.

My clue was

Fay trio with line in weaving? One spins thread.

The second part is the definition (a filatory spins thread) whereas the first part is the word play, FAY TRIO with L forms the basis of an anagram, with “weaving” as the anagram indicator (“anagrind”) instructing the solver to form an anagram.

I think the mythological connection between the two parts of the clue lays a false trail that disguises the definition a bit so I was quite pleased with this effort, thinking it might just get a VHC. I was very surprised to find it winning outright and am absolutely delighted!

I’ve expunged the first line of my address from the scan for obvious reasons, though it is there in the newspaper. I presume it is there because the winner of the Azed Competition not only gets a prize in the form of book tokens but is also sent the Azed Instant Victor Verborum Cup to hold for a month before passing it on to the winner of the next competition, when the result of that is announced, in this case about a month from now. The next Competition puzzle is in next week’s Observer, published on May 2nd. The following day is a Bank Holiday in Ireland so I’ll be able to have a good go at that too.

Presumably the trophy will arrive in the post at some point. With the current state of the mail service between Ireland and the UK I only hope it arrives before I have to send it on to the next winner!

Eye Solved Cyclops

Posted in Crosswords with tags , , , on August 21, 2020 by telescoper

I am a long-term subscriber to Private Eye but since I have moved to Ireland the issues occasionally get lost. This morning I found No. 1527, published on 31st July. It’s too late to send in the crossword for the £100 prize, but I did the puzzle anyway.

I remember a while ago staying with a friend of mine – also an Eye subscriber, but not a crossword fan – and with his permission I did the puzzle in the copy he had lying around. When I showed him the solution he said that even with the answers he didn’t understand it. I think this is not an uncommon reaction from people who don’t attempt cryptic crossword puzzles regularly, so I thought it might be fun to post my solution to this one along with the clues so perhaps you can see how they work. I don’t think the Eye puzzle is really all that difficult, as cryptic crosswords go, although there are some in-jokes and there is quite a lot of fairly coarse humour!

If anyone wants any of the answers explained then please let me know through the comments box.

Incidentally, the person who sets the crosswords for Private Eye under the pseudonym Cyclops is called Eddie James and he also sets crosswords for the Guardian under the pseudonym Brummie. Presumably he’s from the Midlands.