While we have been covering and analyzing primary sources, we covered secondary. Primary sources are firsthand accounts actually written by someone, or created by someone. With secondary, they are secondhand accounts, sometimes written long after the fact but based on research. An example would be of the lost continent of Atlantis.
We have no primary sources at all. If there were primary sources and we had them in our possession, it would instead be the historical lost continent of Atlantis. What is known about it is largely what was written down by the ancient Greek philosopher Plato, thousands of years ago.
Below is the document that was examined today. It is more recent but pretty accurate depiction of what the illustrator thought was a typical scene in a typical home hundreds of years ago. This is based on the illustrator's research but is obviously a secondhand account of someone who was not there.
In science, we did the warm-up and then I demonstrated the three things: the property of reflection, the law of reflection (light always reflects at the same angle from which it came), and that the three primary colors of light are magenta, green, and cyan NOT red, blue, and yellow!