Object of the Month:
Milne-Shaw seismometer

 

Matthew, a Postdoctoral Researcher in Earth Sciences at the University of Birmingham, describes his choice of an early seismometer for Object of the Month at the Lapworth Museum of Geology.

Video transcript here

Hi I'm Matthew and I'm a Postdoctoral Researcher in the Department of Earth Sciences at the University of Birmingham, just upstairs from the Lapworth Museum. My chosen object is this seismometer, the Milne-Shaw seismometer; which is a very, very early example of one of these instruments which used to detect earthquakes. And since I spend my day-to-day life looking at records from instruments not a million miles away from this, I find this an absolutely fascinating and wonderful object.

What we have is an instrument here that was built by a bloke working in a converted greenhouse right at the very start of the subject producing beautiful scientific instruments that have been able to produce amazing records. They’re sensitive enough to detect earthquakes from distant places across the earth but also enough to detect, for example, a passing traction engine.

And one of the things I really like about this instrument, it's not just that it's a beautiful piece of shiny brass and steel and goodness knows what. But I really like that you can see how it works quite easily and we actually have a modern equivalent of this that we used for teaching. It works on exactly the same principle; you have a weight and that stays still when an earthquake happens as everything else moves around it, and that causes a magnet to move relative to an electric coil and that then generates a signal which can be recorded either on a wax disk or with a pen and paper or more recently onto a hard drive. And these are the records of earthquakes that we use in all sorts of science.

What I use is very small versions of these to detect pressure waves in water, but the principle is exactly the same. You have something that stays stationary, something that moves around it and that's how we can detect earthquakes.

Sitting at my desk upstairs and working with the latest technology I find it really reassuring and gratifying that down here in the museum, preserved for the future, is something that is the great, great, great, great grandfather of all the instruments that I'm using.