Long description

Figure 9 shows a spectrum. It is represented by a thin black rectangle in landscape format with five vertical coloured lines positioned along its length. From left to right the lines are: blue, green, two closely arranged yellow and red. The blue line is about a third along the rectangle. The green line is just over halfway along. The two yellow lines are about three quarters along. The red line is between the yellow ones and the end of the rectangle, but closer to the yellow lines.