The Coldest Winter on Record and the Misplacement of Thermometers
200 years ago, world climate teetered on the edge of the Little Ice Age but weather is a local condition. For better or worse, the local temperature can vary from the world average. For Europe, it has become worse... much, much worse. Rivers in Italy are frozen over so that carriages can cross without fear of falling through the ice. It is snowing in Rome. The Great Frost is killing off plants that would normally survive a winter although many of the trees are proving to be more freeze-tolerant than was previously assumed. That does not translate into a particularly good result... just better than expected. The standard thermometer (such as it is and where it is measured) hits its lowest point on December 30th. In London proper, it will hit about -15 degrees Celsius or +5 degrees Fahrenheit. An average low in the modern day London is 15 degrees Fahrenheit but modern temperatures are subject to asphalt and concrete heat retention and release.      
Making Cheaper Cast-Iron Pans *
Blast furnaces use charcoal to smelt iron these days. It is an expensive process requiring labor to cut down trees and then making the charcoal in fire pits covered with dirt and twigs. Coke at this time is made in a similar manner but it uses coal covered in coke dust. Its production is less labor-intensive and produces useful by-products such as coal-gas for lighting street lamps and coal-tar for paving roads. However, these by-products won't come into general use for many years yet. Patents for using coke as part of the smelting process have been around for years but Abraham Darby has made the process commercially viable in England. In fact he will make cast-iron considerably cheaper and he will use this cheaper process to produce cast-iron pots and pans. The higher coke production will also force a lot of charcoal-makers to find a different line of work.  
A Hot Air Balloon on Paper but Not in the Air
A Portuguese priest offers a proposal to the King of Portugal to design an airship that looks suspiciously like a hot air balloon. The priest will come up with a beautiful design... beautiful in the sense that it looks pretty on paper... but it won't fly. He will work on improvements to the design but his efforts will be cut short when he comes under the scrutiny of the Inquisition. He will escape to Spain and die there of a fever in 1724. 
This Year in Wikipedia
Year 1709, Wikipedia.
- London ON Average Temperatures by Month (2016). Retrieved on 14 January 2016. “Average London temperatures: January: High 29F to Low 15F (-2C to -9C)”
- Derham, W. (1708-1709). [URL: http://www.jstor.org/stable/103288 "History of the Great Frost in the Last Winter 1703 and 1708-9 By the Reverend Mr. W. Derham, Rector of Upminster, F. R. S., The"]. Philosophical Transactions (1683-1775) (Royal Society) 26: 454-478. URL: http://www.jstor.org/stable/103288. Retrieved January 14, 2016. "In London the greater Contraction of the Spirits was on January 3, which was an excessive cold Day At Upminster also: But the far greatest Contraction with us was on December 30, before. The reason of the Difference is because my Thermometer is always abroad in the open Air, where no Sun-shine toucheth; but those two London-Glasses are within Doors in Rooms where no Fires are made.".
- Patterson, Louise Diehl (June 1953). "Royal Society's Standard Thermometer, 1663-1709, The". Isis (University of Chicago Press on behalf of History of Science Society) 44 (1-2): 51-64. http://www.jstor.org/stable/227641. Retrieved January 14, 2016. "The history of the Royal Society's standard thermometer properly begins on 2 September 1663 when Dr Wilkins put the company in mind to improve their former consideration of making an history of the weather, in order to build thereupon an art of prognosticating the changes thereof: And he suggested, that it might be recommended to some of the members of the Society, to make constant observations, at least of the most remarkable changes of the weather: in order to which, Mr Hooke was desired to engage herein, which he did; and Dr. Wilkins undertook to recommend the same to Dr. Power.".
- 1709: The year that Europe froze. New Scientist (4 February 2009). Retrieved on 13 January 2016. “IN ENGLAND they called the winter of 1709 the Great Frost. In France it entered legend as Le Grand Hiver, three months of deadly cold that ushered in a year of famine and food riots. In Scandinavia the Baltic froze so thoroughly that people could walk across the ice as late as April. In Switzerland hungry wolves crept into villages. Venetians skidded across their frozen lagoon, while off Italy’s west coast, sailors aboard English men-of-war died from the cold. 'I believe the Frost was greater (if not more universal also) than any other within the Memory of Man,' wrote William Derham, one of England’s most meticulous meteorological observers. He was right. Three hundred years on, it holds the record as the coldest European winter of the past half-millennium.”
- Great Frost of 1709 - Wikipedia (2015). Retrieved on 13 January 2016. “The severe cold occurred during the time of low sunspot activity known as the Maunder Minimum.”
- Little Ice Age - Wikipedia (2015). Retrieved on 14 January 2016. “It has been conventionally defined as a period extending from the sixteenth to the nineteenth centuries, or alternatively, from about 1300 to about 1850, although climatologists and historians working with local records no longer expect to agree on either the start or end dates of this period, which varied according to local conditions.”
- Taylor, George (August 25, 2011). 2997E a weather station located next to an AC window unit. SurfaceStations.org. Retrieved on 14 January 2016. “Forest Grove, looking east”
- Cast iron - Wikipedia (2016). Retrieved on 13 January 2016. “Cast iron pots were made at many English blast furnaces at the time. In 1707, Abraham Darby patented a method of making pots (and kettles) thinner and hence cheaper than his rivals could. This meant that his Coalbrookdale furnaces became dominant as suppliers of pots, an activity in which they were joined in the 1720s and 1730s by a small number of other coke-fired blast furnaces.”
- Flinn, M. W. (February 1959). "Abraham Darby and the Coke-Smelting Process". Economica, New Series (Wiley on behalf of London School of Economics and Political Science Suntory and Toyota International Centres for Economics and Related Disciplines) 26 (101): 54-59. http://www.jstor.org/stable/2551490. Retrieved January 14, 2016.
- Alex Shrugged notes: This account of the banana company comes from a Panama citizen that I interviewed personally, January 13, 2016, 1:00 PM to 1:45 PM. in Austin, Texas.
- Bartolomeu de Gusmão - Wikipedia (2015). Retrieved on 13 January 2016. “In 1709 he presented a petition to King John V of Portugal, seeking royal favour for his invention of an airship, in which he expressed the greatest confidence. The contents of this petition have been preserved, together with a picture and description of his airship. Developing the ideas of Francesco Lana de Terzi, S.J., Gusmão wanted to spread a huge sail over a boat-like body like the cover of a transport wagon; the boat itself was to contain tubes through which, when there was no wind, air would be blown into the sail by means of bellows. The vessel was to be propelled by the agency of magnets which were to be encased in two hollow metal balls. The public test of the machine, which was set for June 24, 1709, did not take place.”