When I was writing for children, I was writing genre fiction. It was like making a good chair. It needed four legs of the same length, it had to be the right height and it had to be comfortable. ↗
Measurements of the specific ionization of both the positive and negative particles, by counting the number of droplets per unit length along the tracks, showed the great majority of both the positive and negative particles to possess unit electric charge. ↗
There were scenes that just for length purposes, and knowing that the attention span of kids is not great, don't make it much longer than about 90 minutes. ↗
The length of exposure (one minute in sunlight) is still too long for the portrait. It was fifteen minutes when I first began my work. Progress may continue. ↗