Limestone – Joyce Janes

‘Come along now stopping chattering and settle down,’ shouted Miss Calcaire.

The noise made by the excited children quietened.

‘Robert I’m waiting.’

She paused then looked around as 28 pairs of eyes stared back.

‘Today we’re going to talk about our trip to Pooles Cavern.’

‘About Robert falling down the steps in the cave Miss,’ shouted Theo.

‘No,’ she said.

‘About Robert missing the coach home,’ shouted one of the girls.

The class erupted into laughter and Robert blushed.

‘Certainly not.  We will be focusing on Limestone, the stalactites and stalagmites and how they are formed.  And if you are really good we will set up an experiment,’ she paused until the excited buzz had stopped.

‘Who can tell me how limestone is formed?’

Hands shot up all over the room.

‘Yes Abigail stand up and tell the class.’

A scarlet faced Abigail rose to her feet and staring at Miss Calcaire said, ‘It’s shells Miss, tiny sea snails and things that died and left their shells behind,’ as she spoke the last few words the little girl, face as red as a beetroot, sank back into her seat.

‘That’s right,’ said the teacher.

‘Thousands of years ago the area was covered by a warm water lagoon.  As Abigail said the water was rich with tiny sea creatures.  As they died their shells sank and layer after layer built up to form the limestone.  Water then seeped between cracks in the rock washing away loose softer areas leaving cracks, crevices and cave.’

‘Who can tell me what forms as water drips into the cave?’

Again hands shot into the air.

‘Robert?’

‘Icicles Miss.’

‘They do look like icicles but what are they called?’

Robert puzzled as the class waited.

‘Strelasites?’ he offered.

Hands shot up.

‘Almost right,’ Miss Calcaire smiled looking round.

‘George?’

‘There are stalactites and stalagmites,’ he told the class.

‘Can anyone remember which is which?’ she asked.

Answers came from every direction and arguing broke out as children argued about which go up and which down.

‘Shush,’ called Miss Calcaire who had drawn a picture on the board and labelling them.

‘As water drips from the roof of the cave tiny particles of calcium build up leaving, as Robert said, icicle shaped stalactites hanging down.  Drips splash onto the floor of the cave leaving tiny particles of calcium and those build upwards and form stalagmites.’

‘Can they grow until they join up Miss?’ asked Theo.

‘Yes can you remember some of the columns, the pillars in the cave originally they would have started out as stalactites and stalagmites.’

The children agreed remembering the fantastic formations they had seen.

‘Think back to what you saw when we visited the cavern and draw a picture of what you remember.’

Immediately the children began drawing.

‘Robert, what are you doing?’ asked Miss Calcaire looking over the boys shoulder at his drawing of stars and lines flying off in every direction.

‘I’m drawing what I remember Miss,’ he told her, ‘that’s what I saw when I banged my head.’

Exasperated the teacher sighed ‘I want you to draw stalactites and stalagmites. Robert please copy what is on the board instead.’

She walked round advising children and eventually everyone had completed their picture.

‘Now for the experiment,’ she announced

‘I want you to work in pairs.’

The children paired up and waited excited at the thought of doing a real experiment.

‘Did you all bring two jam jars?’

‘I forgot Miss,’ Robert told her.

‘I somehow thought you might,’ she smiled ‘its lucky I brought some spares isn’t it.’

She gave each child a piece of thick woollen thread and two heavy beads.

‘Now watch me and copy what I do,’ she told them.

Taking her wool she attached a bead to each end of the thread.

She took a large jug of liquid and filled each of her jam jars.

‘This will be a class example and we will keep it here.’

She took one end of wool with a bead attached and dipped it slowly into one of the jam jars full of liquid.  The other end went into the second jar.

The children watched in silence.

‘Of course you will do this part once you get home,’ Miss Calcaire told them.

She moved the jars closer together so the thread sagged a little in the middle and she placed a saucer underneath the lowest point.

‘Can anyone guess what will happen?’ she asked.

No one could.

She explained, ‘the liquid will be sucked up the wool from each jar and where the thread sags there,’ and she pointed to the wool above the saucer, ’a drip will form and in a week or so a stalactite will form and if we are really lucky a stalagmite may form on the saucer.’

The children gasped amazed at the thought heads filled with pictures of creating their own Pooles Cavern.

‘How can water do that Miss?’ asked George.

‘Oh I forgot to tell you this is very special water.  I dissolved some granules called Epsom Salts in it.  It isn’t dangerous but you mustn’t drink it and always wash your hands after touching it.’

Robert giggled and looked at his friends.

‘I will come and fill your jars just must make sure you put the lids on tight.  When you get home just copy what I did and create your own stalactites.  She walked round the room filling jars.

Robert turned to George.

‘I bet you daren’t taste it?’

George was knew he shouldn’t but lifted the jar to his mouth.

‘Pooh it smells awful I’m not drinking that.’

‘Theo will won’t you?’ Robert challenged.

‘Oh go on then,’ said Theo confident that he could drink it.  He took a sip, ‘its foul,’ he spluttered.

The others laughed.

‘Well I will drink it,’ said Robert and he did the whole jar full.

‘Miss,’ shouted Theo ‘Robert hasn’t got any liquid in his jar.’

Miss Calcaire came over ‘Robert?’ she questioned

‘Yes Miss,’ replied Robert looking a bit green.

‘You didn’t,’ she said knowing the answer already.

‘Robert we need to get you home Epson Salts is a laxative, it makes you go to the toilet.’

Robert didn’t laugh as someone shouted ‘he might turn into a stalactite.

 

Joyce Janes writer for children

 

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