A mackerel sky

MackerelI was inspired to write this post by a visit to the archives of the Met Office in Exeter. The collections hold some absolutely fantastic items, including a printed proclamation issued by Charles II in the mid-1660s ordering a day of fasting and prayer in an attempt to stop the terrible deluge of rain the kingdom was experiencing (which, following the wettest winter on record in the UK, certainly struck a chord with me). As you might expect, Hooke and his Royal Society colleagues were extremely interested in the weather. Hooke and Christopher Wren invented instruments to measure and record weather conditions, and Hooke and a host of natural philosophers across Europe kept detailed weather diaries, sometimes spanning decades. Hooke himself wrote a series of instructions about how best to do this. As well as recording temperature, wind direction and strength, and so on, Hooke suggested that weather-observers note the ‘Constitution & face of the Sky’ as well as any other notable features such as any ‘haloes or Rings’ that might encircle the sun or moon. One problem, though, was the lack of a standard set of descriptions for cloud formations. So Hooke set about creating his own classification scheme.

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A week in the life of Robert Hooke: Sunday 30 March to Saturday 5 April 1673

The weather this week in 1673 was about the same as the weather in 2013 – terrible. Hooke reported cold, rain, frost, and snow during the week. The worst day was 3 April:

a continual snow from 6 in ye morn till late at night when ye wind rose stormy in ye north. Th[ermometer] all day 2. The like day not knowne for cold & snow.

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A week in the life of Robert Hooke: Sunday 16th to Saturday 22nd March 1673

Hooke’s London was experiencing typical spring weather in mid-March 1673: that is to say, a mixture of sun, rain, wind, and clear skies (but no snow, unlike mid-March 2013). Hooke’s weather record for 18 March gives a good feel for this: ‘cleer for ye most part all day but some flying great clouds sometimes intercepted ye Sun’. Despite the generally good weather, Hooke wasn’t feeling entirely well, suffering from feverish symptoms. He felt ‘Guiddy’ on the 18th, for which he took Elixir proprietatis (a well-known medicine made of aloes, myrrh and saffron that was apparently still in use in the 20th century!). On the 19th he ‘went shivering and hazy like an ague to bed burnd about 2 [am?] & sweat much after’. From his diary entry it sounds as though this had resulted from taking Dulwich water (ie. mineral-water from Dulwich), and a ‘spoonful of Andrews’ (possibly spirit of angelica) – but he may have taken these because he was already feeling ill. It’s difficult to say whether cutting his hair ‘short wth scizzers’ was a response to feeling feverish, or just routine maintenance – possibly the latter, given that he’d sent his periwig ‘to be curled’ the previous day. If you look at the portraits of some of Hooke’s Royal Society colleagues (Robert Boyle, for example) you’ll see how luxuriously curly their periwigs were.

The changeable weather and a slight indisposition didn’t slow Hooke down, and he recorded a busy week of work (with, of course, some visits to Garraway’s coffee house). In terms of official work for the City, he visited the Guildhall ‘commissioners’ on the 17th (possibly the Commissioners for Sewers?); produced a certificate for ‘Mr Calmedy’ (the results of his survey of a ground plot); and took a ‘view’ (that is, made a survey) in Queenstreet. The entry for 22nd March is intriguing: ‘at Guildhall wth townclark Gresham Writings Burnt’. Were these ‘Writings’ the records of Sir Thomas Gresham’s legacy? I’m not quite sure why Hooke would have been interested in this, except that about this time planning had begun for the Royal Society’s return to Gresham College, its original meeting-place. Since the Great Fire in 1666 the Society had been meeting at Arundel House on the Strand, so that Gresham College could be used as a temporary Royal Exchange. Could there have been some question as to whether the Royal Society should be allowed back? The only other evidence from Hooke’s diary comes a month later, in an entry for 23 April:
at Guildhall searcht ye Hustings book for Sr Th Greshams house. found he purchasd 2 houses in Broad Street. An[no] 10 Elizabethæ. & one in Bishopsgate Street. An[no] 3o Elizab[ethae] Quere
It’s not clear why Hooke looking into the affairs of Thomas Gresham, but another possibility is that it was linked with some work going on at or near Gresham College at this time. The entry for 18 March says that an unnamed ‘cornchandler broke downe part of Gresham Coll wall. promised inclosing house of office, and yard. made a chimny out of ye Room equall to my Repository’. This is a bit mysterious but perhaps had something to do with a neighbouring property. The ‘house of office’ was a common euphemism for the privy. I guess the room ‘equal to’ the Repository meant the room opposite or next to the Royal Society’s Repository (collection of museum artefacts).

Hooke’s scientific work this week involved a couple of experiments, a meeting of the Royal Society at Arundel House on Wednesday, and some manual work constructing scientific apparatus. The ‘experiment of burning’ had been ongoing since mid-February. The minutes of the Royal Society meeting on 19 February recorded a failed experiment ‘to find, whether the Air increases or decreases by burning’, and according to the minutes Hooke’s apparatus apparently let him down again on 5 March. Hooke himself was convinced that the air decreased with burning and read a lecture to the Society presenting these results on 19 March. Having successfully settled that question, he moved on to an experiment about ‘the penetration of spirit of Vitrioll & water’. Again, the Fellows were curious about whether the mixture of ‘Oyle of Vitriol’ (ie. sulphuric acid) and water would result in a larger or smaller volume than that of the separate liquids. (You’ll have to wait until next week for the results!) The Royal Society also received Dutch microscopist and biologist Jan Swammerdam’s ‘cutts of a frogs Lungs’ – that is, drawings of dissected lungs. They are still in the Society’s archive (along with Swammerdam’s drawing of a cute little rhinoceros beetle).

Drawing of frogs' lungs by Jan Swammerdam, 1673. Copyright The Royal Society.

Drawing of frogs’ lungs by Jan Swammerdam, 1673. Copyright The Royal Society.

Hooke seemingly also spent some time this week working on his ‘arithmetick engine’ or calculating machine. Gottfried Leibnitz FRS had shown such a device to the Royal Society earlier in the year, and Sir Samuel Morland FRS had also produced a working model (Hooke’s judgement? ‘very silly’). Hooke’s engine, of course, was intended to be more elegant and yet more powerful than either of these previous examples. It seems likely that the lathe he bought this week, and the ‘Engin for cutting wheels’ he borrowed from a Mr Bell, were connected with this project. On the 20th Hooke recorded that ‘Mr Stanton shewd me his module of Arithmetick engine’. This was presumably the model of Hooke’s design that he had requested from Stanton earlier in the month.

It was also a good week for books. Hooke borrowed the ‘Description of Ceylon’ from Mr Chamberlaine, which was possibly a Dutch work by Philippus Baldaeus. He also noted that he had seen a German book ‘of mineralls’ that belonged to Henry Oldenburg, the Royal Society’s secretary. He did make one purchase, a fascinating and very beautiful book called An embassy from the East-India Company of the United Provinces, to the Grand Tartar Cham Emperor of China (London, 1673), which he bought for twelve shillings. This was a translation by John Ogilby of a Dutch volume. I haven’t seen the Dutch edition, but the English translation was illustrated with lovely engravings showing details of Chinese life. You can see a digital version of the book here.

That’s all for this week – if you have any questions let me know and I’ll do my best to clarify.

And if you want to find out more, you might be interested in the following:
For more on 17th century medicines see this very interesting article about a medicine chest presented to a young Scottish nobleman by the Grand Duke of Tuscany.

For the minutes of the Royal Society meetings at this period see Thomas Birch’s The History of the Royal Society of London for Improving Natural Knowledge (London, 1756) – free online via Google Books.

To find out more about Hooke’s surveying activities, I recommend Michael Cooper’s ‘A More Beautiful City’: Robert Hooke and the rebuilding of London after the Great Fire (2003).

Watching the weather

Hooke started the first entry in his diary with a weather report: in fact it’s possible that recording the weather was one of the reasons for starting the diary, or memoranda, in the first place. Hooke’s first weather report was for Sunday 10 March 1672:

[mercury] fell from 170 to 185. most part of ye Day cleer but cold & somewhat windy at the South–[I was this morning better with my cold then I had been 3 months before] [moon] apogeum–It grew cloudy about 4. [mercury] falling still

Instead of writing the words ‘mercury’ and ‘moon’ (transcribed in square brackets here), Hooke depicted them with their astrological symbols ☿ and ☽ as a kind of shorthand. For me, the interesting thing about this entry is that Hooke’s own life seems inextricably linked with the weather – he inserts a comment about his cold in the middle of his very first weather report. I think this is a clue to interpreting the weather reports, and thinking about why they appear in what quickly becomes a very personal (and messy, subjective, ‘unscientific’) document and not, for example, in a separate log book (which is what he had advocated to the Royal Society in a paper in 1663). Hooke, and his colleagues in experimental philosophy, had very little way of knowing what information was going to be useful for their scientific endeavours; and they couldn’t predict what sorts of things might influence other things – the effect of weather on human health, for example. One way to get around this was to record as much detail as possible when making observations, so that patterns might begin to appear. So perhaps having the weather reports in a place where they were easily comparable with other happenings (such Hooke’s health, or the moon’s apogee) would be more useful than keeping separate tables.

Hooke had several instruments for recording the weather, but the one he mentions most often in his diary is the barometer. Originally an intriguing instrument for making experimental demonstrations about the nature of air and vacuums, the glass tube filled with mercury gradually transformed into a device for measuring atmospheric pressure, named ‘barometer’ by Robert Boyle in 1663. Hooke described his own barometer at length in the Preface to Micrographia. Micrographia of course is mostly (and rightly) famous for its arresting illustrations of microscopic objects, but the text is also fascinating. In his Preface Hooke makes it clear that one of his hopes for science is the improvement of the human senses – all of them, not just sight. For Hooke, the barometer is not merely a device that measures something, it is a way of enhancing human perception of the effects caused by
those steams, which seem to issue out of the Earth, and mix with the Air (and so precipitate some aqueous Exhalations, wherewith ’tis impregnated) . . .
something of this kind I am able to discover, by an Instrument I contriv’d to shew all the minute variations in the pressure of the Air; by which I constantly find, that before, and during the time of rainy weather, the pressure of the Air is less, and in dry weather, but especially when an Eastern Wind (which having past over vast tracts of Land is heavy with Earthy Particles) blows, it is much more, though these changes are varied according to very odd Laws.

He published a drawing of his wheel barometer in Micrographia.  The ‘J’ shaped glass tube is filled with mercury, and has a sealed bulb at the top but is open at the other end. In the bulb a vacuum provides enough suction to prevent the mercury from flowing out of the tube. At the open end of the tube a ball floats on the mercury. This float is attached to the pointer on the dial by a length of string. If the air pressure rises the mercury is forced up into the bulb and the level of the mercury at the open end drops. As the float drops too, the pointer moves. Hooke's wheel barometer

Hooke eventually stopped incorporating detailed weather reports in his diary entries, but he retained a strong interest in the subject. He wrote a treatise about naming clouds, suggesting a standardised system, and he invented an integrated automated weather-recording device that would punch a scroll of paper recording data about temperature, wind speed and direction, and atmospheric pressure. He also continued to note particularly significant weather happenings in his daily entries. On Saturday 11 January 1690 he wrote:

this night about 1 & 2 of the clock was a most violent Storm or Hurrican which blew down trees houses chimny &c. it blew down part of my parlor chimny. vntiled much of my Long garret. broke windows &c. the B[a]rometer was very low vizt horizontall to the right. vpon the falling of Snow between 2 & 3 in the morn the wind ceased it blew at North. N. W. & N. E. the rest of the night and all next day cleer calm cold & frosty

Hooke and his colleagues were setting the tools in place to enable predictions of rough weather on land and at sea. Unfortunately, we’re not able to interpret Hooke’s data because we don’t know enough about his instruments and scales – or at least, I believe that’s the case but if anyone out there knows differently please get in touch!