Another mark. Note that it is raised slightly
and darker around the edges.
We figure these marks are probably made by tank sparks. (Ring diameter
= 1 cm)
slide changes every 10 seconds
Cleaning the inside of the tank August 2001 |
Another mark. Note that it is raised slightly
and darker around the edges.
We figure these marks are probably made by tank sparks. (Ring diameter
= 1 cm)