Excellent story. The comments from previous workmates give the sense that this was a nice place to work. Here is a puzzle... In my old pre-ubiquitous-computin

Excellent story. The comments from previous workmates give the sense that this was a nice place to work. Here is a puzzle... In my old pre-ubiquitous-computing physics lab we did something similar to the system described in the OA with a large piece of graph paper and a collection of coloured pens. It was called the Who Buys Next Chart. We made our own coffee and tea, you understand. Axes were drawn with number of cups made along the bottom and money up the side. A thick black line of gradient equal to the average cost per cup was drawn(1). Each member had a different colour pen. When you made a drink you extended your line along an amount equal to the number of drinks. When you bought something you extended your plot with a vertical line equal to the amount you spent. Equitable contributions implied a plot approaching the thick black line. When we ran out of a crucial ingredient, the person whose plot had reached furthest left below the line (i.e. who had made the most drinks but not bought much) had to go and buy the stuff. The system was gamed in various ways - or more accurately various strategies evolved to avoid having to go out in the rain and various issues about equitable contribution arose. Can you spot some of the more obvious ones? (1) The gradient was determined by the accumulated result from the previous WBNC. This tradition had been in place for some years, and a large sheet of graph paper lasted for a couple of months.