During the first psychogeophysical summit in London I performed two temperature walks:a spell of cold winter weather. The cold reawakened my interest in temperature - as a phenomenon to be investigated by psychogeophysical and psychogeographical methods.
In recent weeks I've been playing with the four thermometers that are in my possession and they are all very different. They have very different characters and I don't understand them yet:
- The "garden variety" thermometer (the long one) is the easiest to grasp. It measures air temperature. Marcel Minnaert says that you have to swing it through the air "carefully but vigorously" to get a good reading. It is not very accurate but it is quite fast.
- The digital thermometer (white) is quite accurate but very slow. And when I hold it in my hand I never know if I'm measuring the air temperature or my body temperature. Or a mix of both.
- The infrared thermometer (pistol shape) is very accurate and extremely quick, but I'm not sure what I'm measuring exactly. Do I measure real temperature (black body radiation) or just the radiation properties of the object? Or a mix of both?
- The thermocouple that came with my voltmeter (red). Sometimes it gives the same results as the other thermometers and sometimes not. I don't know why.
I have taken my thermometers for walks, but I don't have an intimate relationship with them yet and I cannot write about them as lovingly as Luke Howard does in his "Climate of London" - using scientific but florid Victorian prose:
A Thermometer should be mounted at about five feet from the ground and screwed on a fixed support; not hung up free and liable to swing and strike with violent gusts of wind.There will be more about temperature in future posts. This was just a "warm up" exercise.
The Thermometer may be set facing that part of the general North exposure, where, from the disposition of the surrounding objects, the heat may have the freest radiation to the open sky; a point which late discoveries show to be important.
To the above mounting, it will in some situations be proper to add a small shelter above the instrument, which shall suffice to keep off direct showers at least — and, at a suitable distance on the West side, a shade moveable on hinges, to be interposed, in the heat of summer, between the instrument and the rays of the afternoon sun.