Robert Boyle's weather journal for the year 1685

Abstract

Robert Boyle was one of the most influential natural philosophers of the Enlightenment. Although he recorded fragmentary instrumental meteorological readings in his numerous works, it was generally thought that he did not record observations with the regularity seen in the journals of other late‐seventeenth century philosophers. However, in the Boyle archive at the Royal Society in London is a diary that was recorded while Boyle was living in London and which provides a largely complete record of twice‐daily barometer, thermometer and weather readings from December 1684 to January 1686. As far as I can tell, these data have not been converted to modern units or scrutinised in any systematic manner. In this paper I derive corrections for the instrumental observations and examine the weather descriptions. Although the record is short, it does provide a detailed daily snapshot of weather conditions for this 14‐month period around London. The dry conditions that lasted into early summer 1685 constituted the most prominent feature of the weather during that year. The journal indicates that the winter 1684/1685 was cold and frequent frosts and fog were experienced, although the following winter of 1685/1686 was relatively mild; summer 1685 appears to have been relatively cool. Overall, the data attest to the variety of weather conditions that could be experienced in London during the Late Maunder Minimum.

A fair wind, and a prosperous voyage? – not on 22 December 1684

“…The pressure rose through 22 December to a recorded peak of 29.26inHg (991hPa) at 10 pm that night and pressure stayed close to that until morning (29.23inHg) and declined through the 23rd. In Oxford, 100km to the west, Robert Plot (1685) recorded pressures (Figure 2) that are known to generally match Boyle's record quite well (Cornes, 2020). His readings for the 22nd and 23rd are 29.50inHg and 29.55inHg, with an overnight high of 29.70inHg 5 .…”

“…These five days of changeable winds were preceded by several weeks of winds switching between easterly and westerly, and were followed by westerlies until the 31st when they turned to east again. Gadbury's account is matched to Boyle's notes 2 (Cornes, 2020), reduced here to relevant weather comments and the times of observation. Boyle was living in Central London.…”

A gentleman from Hampstead: statistical weather forecasting in 1750s London

“…Figure 6. Correlation of January rainfall over Eastern Africa (region in black, TAMSATv3) against HadISST SST over 1985-2019 stippling indicates where the correlation is significant at the 90% level (a). (b) shows the scatter plot of mean January rainfall over East Africa (black region, TAMSATv3) against mean January SST (HadISST) over the purple box shown in (a) for 1985-2019.…”

“…The tables seem to display a slowly fracturing health. His introduction noted that such measurements ‘ are best made at some distance from any great city .’ London was prone to toxic fogs: the ‘stinking fogs’ mentioned in both John Gadbury's (1669–1689) and Boyle's diaries (Gadbury, 1691; Cornes, 9). Hampstead lay over two miles northwest of London in open country (Figure 3) and was ‘formerly famous for its medicinal waters’ (Brookes, 3).…”

A survey of the impact of summer droughts in southern and eastern England, 1200–1700

“…Occasionally "quartan agues" or "fevers" are described in the records, i.e. fevers at 3 d intervals, which raises the chances of these references indeed being reports of malaria: in 1222 the source comes from eastern Essex, in 1242 from the well-informed Matthew Paris at St Albans, and in 1557-58 "quartan fevers" seem to have been part of the mixture of disease haunting the English during and after the famine (caused by the bad harvests of 1555 and 1556), although influenza was likely the main culprit of the enormous death rates (Appleby, 1980;Creighton, 1891;Fabyan, 1811;Hamilton, 1877;Holinshed, 1808;Stow and Howes, 1631). For 1252 Matthew Paris writes how the heat lasted throughout the nights, and flies, fleas and other insects made life miserable for men and beasts (see Table 1).…”