Like a minute piece of rock-work

Gertrude Patmore, Our pets and playfellows in air, earth and water, Londres, Bell & Sons, Londres, 1880, p. 148.

….of little new-born fish would glide along near the surface like faint, silvery clouds. In the spring-time there were always quantities of caddis worms. They are the larvae of the may-flies, and move about with their neat litle houses, cleverly built out of tiny pieces of wood and straw stuck together, like a minute piece of rock-work, from one two inches long.
On a Bright, warm day the water would be studded over with spots of dazzling light; these were the smaller water-spiders, who..