These days, tanning a hide is an automatic process that generally involves chromium sulphate, a kind of salt, as the tanning agent. However, back in the days when there was no chromium sulphate, hides were cured using a process called brain tanning.

What you do after skinning the animal is to scrape all the bits of flesh off the animal hide (broken glass works well) and stretch it and salt it to dry. The hide will become stiff. Then you take the brain of the deer and put it in a bucket with some water and heat the mixture. You rub brain solution on the hide as if you are applying sunburn cream. The brain contains oil called lecithin that serves as a natural tanning agent. Tribespeople first practised this method of brain tanning and continue to tan hides with it today. Ironically, buck have just enough oil, or lecithin, in their brains to adequately tan their own hides.

Good. Y’all got that? As an alternative to scooping brains into a bucket, you could just buy an automatic tanning machine and use that to cure the hide. The point that should not be forgotten is that you could do it with brains. You could always do it with brains. It is only modern times which allow us to use machines and chemicals. This, naturally, brings us to acoustics.

Wallace Clement Sabine was, in 1895, given the task of acoustically improving the Fogg Lecture Hall. It was noted that lectures were unintelligible. Sabine tackled the problem by trying to determine what made the Fogg Lecture Hall different from other, acoustically acceptable facilities. Using an organ pipe and a stopwatch, Sabine performed thousands of careful measurements and determined that a definitive relationship exists between the quality of the acoustics, the size of the chamber, and the amount of absorption surface present. He formally defined the reverberation time, which is still the most important characteristic currently in use for gauging the acoustical quality of a room, as the number of seconds required for the intensity of the sound to drop from the starting level, by an amount of 60 dB (decibels). Now, it happens that we have in our offices a number of instruments which allow us to measure reverberation time electronically. It is very simple: connect a cable to a powered loudspeaker, turn the instrument on, push ‘start’ and wait. It happened that we had to determine the speech transmission intelligibility index at a hall in Durban. I told the staff: Go measure the reverberation time and take the value and we will work it out from there. Oh, they said, we do not have an instrument that measures reverberation time in Durban, only a sound level meter. So, I said okay, set up the meter, get a stopwatch, get some balloons and use them to measure reverberation time. Oh, they said, how? And they said they had not got a stopwatch. I said, use your cellphone as a stopwatch. Blow up the balloon, pop it and look at the sound level meter to get the level and measure from the time of the pop until the meter reads 30 dBA less. It dragged on. They said that the test would not be accurate. I said, heck, you have a packet of balloons. Do it 20 times. It will be accurate enough. Queries flew back and forth.

But it was an education for me. I realised that younger people (say in their 30s) really need digital technology to do measurements. They are untrusting of original methods of measurement. I have quoted one example, but it is everywhere: they try to measure electrostatic charge using a multimeter on a volts scale (you should use an electroscope). They need a laser instrument to measure distances instead of a tape measure (admittedly, it is quicker).

Certainly, you may never have to tan a buck hide with brains. But at least you should know how it was done in the past so you can fall back on that if need be.