I’m slowly researching a number of old military technology books (if I can describe them as that) written several hundred years ago. Every so often I come across something intriguing. Here’s today’s.
Conrad Kyeser lived between 1366 and about 1405. He was born in Eichstadt in Southern Germany but lived for a time in Prague. I have referenced his book “Bellifortis” in my last post. The book was written in (poor) Latin and contained many illustrations. Kyeser clearly copied a number of other military technology books, but there was also new material. It exists today with several versions. Some of the technology discussed is remarkable for the time of writing – paddle powered boats able to move against a current, diving suits with some form of stored air for breathing, and a variety of explosive devices, rockets and multi-barrelled revolving firearm systems. The rocket discussion includes remarks on the need for a combustion chamber (described as a “seele” or hollow in the propellant), and that the rocket cylinder/case must be gas-tight.
But here’s something very interesting – a buried IED detection technology. Kyeser describes burning a resin to create a volume of dense thick smoke, contained under an inverted tub. Once a dense cloud is formed the tub is lifted off and the dense smoke allowed to spread across the ground of an area where a buried explosive device is suspected. Kyeser claims that if the smoke rises at any point, that is an indicator of disturbed earth, and the potential that an explosive device has been buried there.
Now that’s an interesting idea, but on the face of it, I don’t have any particular belief that it might work. If a heavy gas rises it perhaps could be due to convection, but why would disturbed earth have convection , I assume associated with a thermal energy release from disturbed ground? I can imagine certain theoretical scenarios where a dark soil is exposed as the device is buried and that causes slightly more solar energy to be absorbed, and then released, but that’s perhaps stretching it a bit. Maybe a buried barrel of gunpowder previously stored in a building would retain its heat long enough when compared to the cold earth in which it was buried and that could cause some convection for a short time. I wonder how long….
I welcome any readers who might have a better explanation, email me at the email address explained above right.