For me, the strongest of the three essays, was the second one on mirrors and reflection. However, there's a lot to 'reflect' upon across the three pieces. The first one is very informative, and probably the most science-y, with a lot of numbers and facts about glass and what it is (and isn't). The last one is about light and how we have started to understand it, but it still has a lot of mysteries to discover. I read each one separately, and would recommend that as an experience to sit with each one and it's musings for a bit before carrying on to the next.