A unique time-keeping machine made by one of Birmingham's great leaders of the Industrial Revolution is to be auctioned tomorrow.
A floor-standing regulator clock, believed to have been designed and built by celebrated inventor and gas and steam engineer William Murdoch, will be auctioned at Bonhams' Sale of Fine Clocks & Barometers. It is expected to fetch between £10,000 and £15,000.
The regulator, which stands in a solid mahogany and oak case, is thought to have been designed by Murdoch for his personal use because it displays many characteristics unusual to those made by traditional clock makers.
It is more like a contemporary scientific or nautical instrument than a clock, and some parts resemble mechanical parts made by Murdoch for other items.
James Stratton, director of clocks and watches at Bonhams, said: " Murdoch's greatest single contribution to the world is his discovery of gas lighting - it was widely known that when certain coal burned it emitted a flammable gas.
"Murdoch spent much time experimenting with this and by 1794 had reached the stage where he could illuminate his own house with gas light. Within three years of his appointment as manager of the Soho works in 1798 he had rigged the building to be lit entirely by gas."
Mechanically, it differs to regulators made by traditionally trained clock makers, Mr Stratton said.
The plates are placed much closer together than usual, the pinions are of a far higher count, the maintaining power is of a most unusual form and the great wheel has 360 teeth and is very large.
The cast iron pendulum bracket is very similar to a bracket used on Murdoch's oscillating cylinder engine of 1785.
Murdoch was born near Ayrshire, and walked more than 250 miles to the Watt and Boulton factory in Soho, Birmingham, to pursue his dream of working with steam engines.
He was immediately employed, and for the rest of his life worked with James Watt and Matthew Boulton. All three are buried in the crypt of St Mary's Church, Handsworth.