« Ordnance Survey and the Jacobite Rebellion | Main | Doing something »
February 27, 2009
To the men who make the machines that make the machines.
It’s all very well having posh instruments – all manner of adjustable gauges and scales that can measure stuff to within a whiff of a whisker – but what do you use to measure the machines that make the measuring instruments?
Ramsden’s Dividing Engine
You need a Dividing Engine, that’s what. Before the invention of this device for dividing other devices, people marked up measuring instruments by hand. So your calculations were only as good as the craftsman who scratched the brass in the first place, and if he’d had a bad oyster for lunch you could be miles out.
an octant built by Jesse Ramsden
Scribing increments on a straight edge was one thing, but scribing divisions on a curved surface was the problem. Navigation and surveying instruments relied on calibrated arcs to calculate their findings.
In 1773 Jesse Ramsden, born in Halifax, in the West Riding of Yorkshire, built the first Dividing Engine.
Jesse Ramsden
Ramsden’s engine meant that sextants, octants and theodolites, amongst other mathematical measury stuff could now be produced consistently, reliably and accurately.
This was thought to be one of the main causes of The British Empire.
Posted by john at February 27, 2009 09:04 AM