Depression @[email protected]

I got a very special present from my PhD student on finishing their PhD.

In 1937, IBM launched the IBM 805 Test Scoring Machine, the first device for processing standardized tests. However, the marks could only be read using a special graphite that was highly conductive. This lasted until the 1960s when the electrical conductivity method was replaced by optical mark recognition.

The Dixon company produced this pencil, the Sense-a-mark 2100, for a long time but now it is a collector's item.