Inventions in the Classroom
Who invented them?
Edwin Binney and Harold Smith founded their company – Binney and Smith, Inc. – in the late 1800s in New York. They began making slate pencils for children. In 1902 they won a gold medal at the St Louis World Exhibition for their newest teaching product – dustless chalk. While touring schools showing the products, the men saw a need for affordable, safe colouring crayons for children.
Crayons at this time were dull in colour (usually red and black), clumsy and mainly used in industry. Binney and Smith set about creating ‘kid-friendly’ crayons using paraffin wax and industrial pigments.
In 1903 the first of that now-familiar green and gold box, containing 8 coloured crayons, appeared. They were called ‘Crayola™’ crayons – crayola meaning ‘oily chalk’. The crayons were an overnight success and, as we all know, are still extremely popular now.
The ‘Lead’ Pencil
Scribes in Ancient Rome used a thin metal rod called a stylus to write on papyrus. Other early forms of the stylus were made of lead. We still call the pencils ‘lead’ today, but now they are actually made from graphite.
Graphite became widely used after a large graphite deposit was found in England in 1564. Graphite was better than lead because it left a darker mark. But it was softer and brittle; and it needed something around it to hold. At first the graphite was wrapped in string, but later people started to encase it in wood which had been hollowed out—and so the forerunner to the pencils we use today was born!
Did You Know?
… a regular pencil can write 45 000 words or draw a line 56 km long!
Chalk – that substance from which the teacher’s nickname, ‘Chalkie’, is derived! You all use it, but what exactly is it and how did it get in the classroom?
Chalk is a soft white limestone formed as mud on the bottom of an ancient sea which, unlike other forms of limestone, does not change into hard rock – that is, it’s easy to rub off!
How do you make chalk? See below!
- 1 cup plaster of Paris
- 1/2 cup of cold water
- icy pole moulds (toilet paper tubes also work well)
- tempera paint (powdered is best)
Combine plaster of Paris, water and tempera paint. The amount of tempera you add will determine how dark the coloured chalk will be. Pour the mixture into icy pole moulds and let dry. Take the chalk out of moulds and use for drawing on the footpath. This chalk will be most effective right after taking out of the mould.
- Lining your mould with wax paper makes the chalk easier to get out.
- Mixing a small amount of acrylic paint as well as tempera works well for colour also.
Recipe source: www.kinderart.com/kitchen/chalk.shtml
An eraser is a piece of rubber or other material used to rub out marks made by ink, pencil or chalk. The modern eraser is usually a mixture of vegetable oil, fine pumice and sulfur bonded with rubber. The mix is processed, pressed into a shape and treated to give it greater elasticity and durability.
Where did the eraser originate?
In 1752, reports suggested a sticky gum from certain South American trees was being used to erase black lead marks. It was named rubber in 1770 by English chemist, Joseph Priestley.
In 1858, the first patent on the pencil and rubber combination so common today was issued to Joseph Rechendorfer of New York City.