Puzzlemaster

"YOU'RE DOING what?" hooted Lesley and Sarah as I blurted out that I was writing about rubber bands. It was late and I was buying mince pies and a coffee at their stall at this year's Didcot Street Fair.

The Broadway had been closed to traffic for the evening and the Christmas illuminations (for the most part coloured lights strung between lampposts) were all lit up (and so was I).

I threaded my way through the throng thinking that what Didcot really needed was a good town song: something along the lines of "Give my Regards to Didcot Broadway", perhaps. I had just detected an obvious flaw in the line "Didcot - so good they named it - once!" when I happened on Lesley and Sandra's stall.

All profits to the PTA, the sign said. Should I buy, I wondered, or was I just perpetuating underfunding in schools? We discussed it over coffee and mince pies and also why the neighbouring Boy Scouts' stall was closed. Was it already past their bedtime?

To tell the truth I felt a little miffed. I hadn't scoffed at their stand. I hadn't poured contumely on their teapot or mocked their mochas. Writing about rubber bands - I pointed out - may not be everyone's cup of tea, but it's a hard job and someone's got to do it. Besides, many things that seemed absurd only seemed so at first sight.

For example, when I had first spotted these pie-vendors, had they not just run out from under their awning yelling "Helter-skelter! Helter-skelter!"? Well, this surreal state of affairs had been adequately explained when it became clear that the stall they manned shared the same generator as the helter-skelter, and their lights had just dimmed.

Another example? Lesley's husband had been driving to Reading earlier that day, when his car had started to smoulder. He had ran into a nearby DIY store, found a fire-extinguisher, queued to pay for it and returned (hotfoot, we assume) to find the car more in need of the fire brigade than an extinguisher. I rest my case.

To be fair, once the pie-vendors had got over the absurdity of my quest they proved a mine of laggy-band-lore. I soon realised that the few uses I had mentioned of the humble elastic band last week were just the tip of the rubberberg.

There was the rubber band trick (see above) which works even if you are clumsy. A band is looped around the index and middle finger of one hand. The fist is then clenched and when the hand is reopened the band is seen to have transferred to the other two fingers. How is it done?

Then there was the RBB. Apparently schoolchildren still pester postmen for rubber bands to amass into a ball, though I doubt whether any such schoolkid versions measure up to the Milwaukee Ball, which as of 29 July 1998 allegedly weighed 140lb and had a 20in diameter.

The process indulges your collectomania, and the primitive drive to go one better than yourself and others. At each stage of its accrual you have a ball that bounces, and soothes the hand that squeezes.

If you hate journeys but like arriving, or are too busy, unmotivated or proud to grow your own RBB but want all the advantages of executive stress-relief, you can still climb aboard the rubber bandwagon by buying one ready-made from the Hawkin's Bazaar Catalogue.

The blurb describes the RBB as "a cricket-size ball" (which I take to mean a "cricket-ball-size ball") that you can give to almost anyone (I like the "almost"). It continues in that wonderful way advertisers have of crossing Ts before you come to them:

"Whenever you need a rubber band you have one and whenever you have a spare one you have somewhere to put it."

I rest my case yet again.

Solutions to last week's puzzles

1. Tilt the rainbarrel until the oval formed by the surface of the water just meets the rim. If now the oval is just touching the bottom rim, the barrel is exactly half full.

(For what sort of containers will this trick work?)

2. Any number ends in the same digit as its fifth power. Seven raised to the 995th ends in 7, so 7 to the 999th must end in the same digit as 7 to the 4th (2401), ie 1.

Point to ponder

An escaped monkey throws the switch on a string of bulbs stretching the length of Didcot Broadway. On the first throw every bulb changes state; on the second every second bulb changes state; on the third every third and so on, until no further changes take place. At this stage 99 bulbs are off. How many bulbs are there?

(For a bulb a change of state means if it was off it goes on and if it was on it goes off. All the bulbs start off, off.)