Cethosia Biblis Larva Hatching
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Tag Archives: MoBot
Punched Tape
Perforated paper tapes were first used by Basile Bouchon in 1725 to control automated weaving looms. I first used these tapes in high school, in the early 1970s for the storage of computer programs. In school, we used one-inch wide, 8-hole paper tape. We used a TTY terminal, like the ones whose sound has been adopted as a shorthand sound effect for breaking news. Our TTY would both punch and read these tapes. In-between classes we would store these rolls of paper tape in old 35mm film cans. Some of the guys even fashioned so-called utility belts in which to carry them around, Batman style. We thought that they were pretty cool. Yes, we really were that geeky. An important difference between these two pictures is that the one below shows the real paper tape. It is nine holes across. Eight holes to store the individual ASCII characters, plus a ninth row of holes that acted as a guide for the punch hole reader. The photo above in not rows of paper tape at all, but a metal screen that is now in the Missouri Botanical Garden’s new visitor’s center. The sunlit shadows only enhance its esthetic. It also has nine holes across each strip, but nine holes for information instead of the usual eight and no line of guide holes, but maybe its artist was going for hexadecimal over ASCII? After all, it is the 21st-century.
White Powders
Diatoms are single-celled alga which have a cell wall of silica. Many kinds are planktonic, and extensive fossil deposits have been found. When we were in the Garden this week, at the home gardening center, I noticed that many of the plants had been dusted with a fine white powder. I asked a gardener if it was an insecticide? In a sense is was and it wasn’t. It was diatomaceous earth.
Composed from the bones of millions of microscopic diatoms that over the millennia had built up into a sedimentary layer, diatomaceous earth is sold as a natural alternative to chemical insecticide. Its sharp silica bones act as an irritant to insects, getting into their exoskeleton’s joints and tearing them up. It is less dangerous to humans than conventional insecticides, but care in its handling must still be taken. It is much safer to the environment than most insecticides.
In the play that we saw this week, Mlima’s Tale, the actor portraying the elephant Mlima, first smears his torso and face with white powder, evoking the ritual body painting of African tribes. This powder has a way of transferring itself, as an emblem of complicity, as each player playing a link in the chain that is the illegal ivory trade, is marked with a white powdered handprint on their bodies. In this instance the white powder was likely talc, but I wonder if the choice of its white color was supposed to be evocative of powdered ivory. Powder created when the ivory tusks are carved into objects d’art, their final form.