31 March 2009

A different kind of strength

A weekend purge of my supplies cupboard (very therapeutic; thoroughly recommended!) turned up a forgotten supply of scritchy-scratchy sandpaper.  Which was crying out to be put to some use.

What could be better than to use it to test the strength of paper?  But hang on; haven’t we done that already?

Well, yes – and no.  Yes, we have found out the strength of paper.  But this is a different kind of strength.  This time we will be seeing how may times a strip of paper can be rubbed against a piece of sandpaper before it tears, or wears out.

Again we will test our familiar three kinds of paper; pink A4 writing paper, newspaper and paper towel.

Each strip of paper will be rubbed back and forth across a piece of sandpaper (which has been taped over a block of wood to make it easier to hold).

IMG_1429 IMG_1430

A careful note will be made of the number of rubs needed to wear out each type of paper.


At the same time, a careful observation will be made of what happens to the paper as it is being rubbed across the sandpaper.  Look what happened to this piece of pink A4 paper:

IMG_1433 IMG_1436

How was that different from what happened to the paper towel?

IMG_1434 IMG_1437

And what about the newspaper?


Now ask yourself; did each group get the same results? 

IMG_1445   IMG_1448

Why do you think this was?  Quentin told us that he and his group rubbed their strips of paper across the edge of the sandpaper block.  They rubbed really fast!  Their paper strips wore out after just a few rubs. 

IMG_1447    IMG_1435

Tatiana and her group were still rubbing away when everyone else was finished.  They rubbed across the top of the sandpaper block and quite gently.


Now, I’m not sure about you, but I certainly know who to ask the next time I have any woodwork that needs sanding!

27 March 2009

Preparing the beds

Under the watchful gaze of the friendly scarecrow, our winter wheat is continuing to flourish.


Behind his (her?) back, all is busyness, as 24 eager Gardener’s Apprentices…..


learn that today’s task is to ready the raised beds for Spring planting.  What, though, lies behind the mysterious shadow (a welcome moment of sunshine, that!) in the red plastic bucket?


And why would we need to use a measuring tape as well as a rake?


A peek inside the bucket revealed coils of string and scissors.  Hmm.


What exactly would we be doing?  Well, the beds would have to be raked…..


and any remaining large stones removed.  Fat worms, though, would stay firmly put.

Meanwhile, the dimensions of the beds (the length and the width) would have to be measured.


String would be cut to size…..


and tied…..


criss-cross across the bed…..


in order to mark out the planting areas.


Sweet William plants…..


and fuzzy-leafed sage…..


are ready to plant.  Seed potatoes…..


and peas, radish, lettuce and carrot seeds….


are on next week’s task list.

What is a Stig?

There was somebody there – or something.  But what?  What do you think it could be?

Tommy, who had sneaked a peek at the picture on the cover of the book, thinks that ‘one of the boys threw a piece of flint; it cracked and it hit Barney.  Barney did not see them.’


Sharukh had the idea that it was something; ‘lots of pieces of chalk and Barney thought that was a person’.

Leon thinks a somebody.  ‘I think he saw a person.’


Aabis, remembering what we had said about people digging for chalk, thinks ‘it was a man that was about to find a crystal’.


Thomas picked up on the reference to old man’s beard.  ‘I think it was an old man with a long beard,’ he tells us.

Tatiana thinks that ‘Barney saw a bear because animals live in caves like bears’ (sic).


However, Virginia thinks ‘it is three ghosts and I think that he saw a shadow’.


Shani too liked the idea of something fantastical.  ‘I think it’s a witch that tied Barney up.’


Raamy thinks ‘he saw the shadow of a monster’.  A pretty scary-looking one at that!


Chloe wasn’t sure.  ‘I think there was a troll, because trolls live underground.’


Or maybe a ‘rabbit because rabbits like to dig’.

Owen thinks ‘it was the bicycle because maybe when he fell in he hit the bicycle and then it flipped up and went out of the pit’.


Sivert too had the bicycle in mind.  ‘I think he saw an old tree and an old bike.’


What do you think it was?  Was it a somebody – or a something?  Was it a Stig (whatever one of those is)?

26 March 2009

Into the chalk pit

We began a new ‘read-aloud’ book on Thursday.  A book that was written quite a long time ago, by a man called Clive King.  A book called ‘Stig of the Dump’.

A preparatory discussion cleared up that by Dump, the author meant a place where rubbish was left; rubbish like wrecked cars and old bicycles; empty oil drums…..


and glass jars.

But try as we might, we couldn’t decide what a Stig might be.  Time to begin I think.

The opening chapter introduces us to Barney, a boy who was staying, along with his older sister Lou, with his grandparents.  He is bored and planning a visit to the old chalk pit; somewhere that incidentally, he has been warned about going too close to.  Somewhere with hidden dangers…..

But Barney being Barney (and I suppose boys being boys) decided to ignore those warnings as he ventured rather too close to the edge of the pit…..


where the tree roots were exposed and the chalk was all dry and crumbly.  And where, if he looked carefully down towards the bottom, he could make out what looked tantalisingly like the propeller of a plane and perhaps the buckled wheel of a bike.

And then suddenly, before he had time to think, he was tumbling over and over, down to the bottom, bouncing from branch to branch, getting tied up in strands of ivy…..


and a tangle of old man’s beard on the way.


Luckily his landing was softened by a bed of moss.


When he opened his eyes he seemed to be lying on some kind of platform, with his feet secured above his head.  And as he peered into the gloom he realised that there was somebody there – or something.

Another look at paper

We were wondering; is the strongest paper also the one that sucks up the most water (or most absorbent)

Virginia thought back to when we had looked at different kinds of paper using a microscope.  She remembered that the fibres of each piece of paper left holes and that paper towel had bigger holes than A4 writing paper.  She also noticed that paper towel is thinner than A4 writing paper.  She thought that meant the water would probably go into the holes (a bit like in a sponge).

And how would we test to find out whether she was right?

We would take three identical (same width, same length) strips of the paper we used before (how strong is paper?)…..


those being newspaper, paper towel and A4 writing paper - and attach them to a strip of masking tape.  This we would stick to the back of a chair so that the ends dangled downwards.


Next we would rig up a dish of water beneath the paper strips so that the ends dipped into the water.


We would leave the paper strips in the water for exactly one minute (which of course we timed accurately with a stop-watch).


Then we would measure how far up the paper the water had crept in one minute.


The newspaper:


The A4 writing paper:


The paper towel:


Then we would record our results in a table.


Which type of paper did we find was the most absorbent?  Why do you think this might be?  Next time you wash your hands, think; which paper would I choose to dry my hands with?