Affiliates
free forum

Keywords

Search
 
 

Display results as :
 


Rechercher Advanced Search

July 2017
MonTueWedThuFriSatSun
     12
3456789
10111213141516
17181920212223
24252627282930
31      

Calendar Calendar


Chalkboards

View previous topic View next topic Go down

Chalkboards

Post by abdulla_uk on 13th December 2013, 7:47 am

Chalk board blackboards go back to the first organized school classroom. Probably, several 100's of years ago. Before that, they used a charcoal stick and wrote on any flat surface available. The problem being, charcoal doesn't erase, so a new writing surface was required very often. Before they needed Chalkboards, somebody had to invent chalk for the chalk boards. It was discovered crushed up limestone produced a white powder that could be compressed into a soft white stick that would make a white line as opposed to the black line that a charcoal stick left. The best part was that it erased off of a smooth stone surface. Then some bright fellow cut thin slabs of slate rock, polished it and the chalkboard was born.

abdulla_uk

Posts : 554
Reputation : 3
Join date : 2013-05-29
Age : 21
Location : UK

View user profile

Back to top Go down

View previous topic View next topic Back to top


 
Permissions in this forum:
You cannot reply to topics in this forum