It usually takes a chain of failures to create an accident

That is how experts explain it when an aircraft or train crashes - something which is not supposed to happen.  Or when a nuclear plant goes haywire.  Anyway, even in our not-so-foolproof lives the same thing can cause us anything from mirth to misery.

In our previous house the insurers demanded that we install either burglar-proofing or an alarm system.  With large picture windows burglar proofing was not the clear favourite.  So: an up-to-the minute alarm with remote call-out of the police, remotes to arm and disarm, cat-proof motion detectors, and all, was installed.  Spiders on the sensors caused a few daytime alarms but it worked well, human error excepted.

Then came the night of high drama - the one where we had a chain of failures.

Mollie (our poodle) was still young enough to sleep next to the bed.  She was not alarm-safe, being a standard poodle in the making (hitch 1).  We normally disabled the sensor in the bedroom when we slept - the one in the passage was protection enough (hitch 2).  I used the remote to turn the alarm on at night once we were sure we were in bed for the duration; that's how it was disarmed in the morning too (hitch 3).  Our son in Florida knew about time differences (hitch 4).  Can you see where this is going?

Yes, he phoned at about 8 or 9 pm - a good time to phone if you are in Florida.  This translates to the small hours in South Africa.  OK, phone in the bedroom rings, wakes everybody, especially Mollie.  Mollie leaps up and sets off alarm.  Alarm alarms Mollie and she starts barking.  Now we have the phone, the hellish alarm and the barking.  I have no idea whether Antony heard any of the chaos when I picked up the phone or whether we had managed to silence the alarm and the dog by then.  There was of course the looming possibility that the police would be hammering at our door imminently.  It was a memorable night.  There was not a lot of sleeping after that.  And, Antony, I always love your phone calls, whatever the time, whatever the consequences.

We don't have an alarm in this house.

Language teachers look away now!

I was marking a set of exam papers written by 120 fifteen-year-olds.  One of the questions required a single-word answer: isosceles.  Please note that this word appeared on the exam paper in another place.  All 120 of them gave the "correct" answer, in that it was there, and it was understandable.

Afterwards, I collected all these isosceleses  and discovered that it is possible to spell the word wrongly, but understandably, in at least twenty-seven different ways.  For the reader's delectation, I give them all here.

ilsoslens; iscoseles; iscosolese; isoceles; isocelese; isocelles; isocles; isocoles; isocolese; isosalease; isosales; isosceles; isoscelese; isoselas; isoseles; isoselese; isosicles; isosiles; isosles; isoslice; isosoceles; isosocles; isosolees; isosoles; isosolese; isosolies; isosolies; issoles

The trick is to find the correct one (as there are twenty-eight, and I found twenty-seven wrong ones, it must be there!) (and no, we don't penalise spelling errors in maths papers) in this alphabetical list.