There was a time when, through the proliferation of steam power, coal extraction in vast quantities became economically viable. Throughout the U.K. coal was burned to make steam for locomotives, factories and ships. It was the domestic fuel of choice. The price of cheap coal was pollution: the skies over many cities were black with soot when coal was king.
... nothing surely was ever more dirty, inelegant, and disgusting than a common coal fire.
Sir Benjamin Thompson, Count Rumford, was born in Woburn Massachusetts in 1753. He is famous for quite a few reasons. He is known in the world of science for his work on the nature of heat. Less well known is his contribution to the American War Of Independence. A major in the New Hampshire militia, he was also a British spy, which did little to endear him to his fellow citizens in New Hampshire and Massachusetts.
Although sadly lacking in expertise in the art of making friends, Rumford was an expert in the art of making a fire. Having made a study of the physics and chemistry of heat and of ignition, combustion and explosion, Rumford published two historically important essays on fireplaces: Essay IV of Chimney Fireplaces, first published in 1796, and Essay XI Supplementary Observations concerning Chimney Fire-places, published in 1798.
I have often wondered that no attempts should have been made to improve the fires which are made in the open chimneys of elegant apartments, by preparing the fuel; for nothing surely was ever more dirty, inelegant, and disgusting than a common coal fire.http://www.rumford.com/articleWhat.html
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The enormous waste of fuel in London may be estimated by the vast dark cloud which continually hangs over this great metropolis, and frequently overshadows the whole country, far and wide; for this dense cloud is certainly composed almost entirely of unconsumed coal, which, having stolen wings from the innumerable fires of this great city, has escaped by the chimneys, and continues to sail about in the air, till, having lost the heat which gave it volatility, it falls in a dry shower of extremely fine black dust to the ground, obscuring the atmosphere in its descent, and frequently changing the brightest day into more than Egyptian darkness.
In his essays on chimneys and fireplaces, Rumford explained the importance of the restricting throat and the use of refractory materials and reflecting surfaces in obtaining maximum heat input into a room for a minimum amount of coal. Those improvements were widely adopted in the design of steam locomotives.
Rumford's military experience with gunpowder led him to experiment with different ways in which large quantities of heat may be obtained. In the modern age he may have had some difficulties with health and safety legislation:
These kindling balls may be made so inflammable as to take fire in an instant, and with the smallest spark, by dipping them in a strong solution of nitre and then drying them again;In the same year that he published his essay XI on chimneys, 1798, Rumford published a scientific paper in the Philosophical Transaction of the Royal Society: An Experimental Enquiry Concerning the Source of the Heat which is Excited by Friction.
Boring Science
Rumford observed that the boring of cannon caused heat through friction. The prevailing scientific theory about heat at the time was that heat was a fluid called caloric. which flowed from hot to cold bodies. Rumford showed by experiment that the friction produced by boring provided a quantity of heat sufficient to boil water and that the heat extraction effect of the water did not change the specific heat of the barrel metal on being reduced to shavings.
I cannot begin to describe the surprise and astonishment expressed in the faces of the bystanders, on seeing so large a quantity of cold water heated, and actually made to boil, without any fire. Though there was, in fact, nothing that surprised me about this event, I have to admit that it afforded me a degree of childish pleasure.
This experiment is often reported as a boring cannon experiment. In fact it was a boring lump of brass experiment1. This boring experiment was an important milestone along the road to the discovery of the laws of thermodynamics. It showed by scientific demonstration that mechanical energy could be used to raise the temperature of a substance. Rumford's experiment inspired the later investigations of James Prescott Joule in the 1840s, of which more later, in another article.
[1] - http://zappa.mit.edu/3.20/images/f/f2/RumfordPaper.pdf
The next article in this series is:
How Can Ice Work Like A Horse?
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