About felicityhen

I am a historian of science, particularly interested in early-modern intellectual history and the social world of the early Royal Society of London. I am currently editing Robert Hooke's diary for publication.

Printing with Tallow . . . ?

While editing Hooke’s diary this week I came across the following nugget of information in an entry for 27 January 1673:

Dr Pell told me that somewhere in Porta was a way deliuered of stamping letters & figures in Sallow and afterwards plaining them almost out then steeping or boyling them in water wherby the letters would swell outwards and be fitt for printing or ye like or be embossed wth heads or the like.

Hooke and the other Royal Society Fellows were extremely interested in mechanical processes, and Hooke mentions new ways of printing or engraving quite a few times in the diary. Unfortunately Dr Pell’s rather vague reference ‘somewhere in Porta’ hasn’t yet helped me to track this particular suggestion down. Giambattista della Porta was a prolific Italian Renaissance author whose best-selling book ‘Natural Magick’ contains lots of interesting information about useful things you can do with science, including sections ‘on counterfeiting precious stones’ and ‘on beautifying women’. You can read the English translation online here  – but please don’t try the white lead cosmetic preparations at home.

What caught my attention was the fact that in the 1935 printed version of the Diary, the section quoted above had come out as ‘a way delivered of stamping letters and figures in tallow and afterwards plaining them almost out then steeping or boyling them in water’ . . .

Now, tallow, as we all know, is a kind of fat, and therefore probably not much use if you intend to boil your letters before printing with them. Whereas sallow is a willow plant – much more suitable for stamping, planing and boiling. Why did Hooke’s 1935 editors print ‘tallow’ for ‘sallow’? Probably because Hooke’s initial ‘s’ looks a bit like a ‘t’ in the manuscript, and tallow is a more commonly used word than sallow (or at least it was in the 20th century – I guess neither is particularly common now), and they weren’t thinking very hard about what they were writing. It’s easy, as an editor, to see the words that you expect to see, especially in Hooke’s rather cramped lines of text. I was pleased to find this, of course, because it reminds me that the mammoth job of re-editing the diary is actually worthwhile! But it also confirms with me again the importance of going back to the manuscript, even when there’s a printed text available. How many readers of Hooke’s diary over the years have scratched their heads over this section and wondered what on earth Hooke could have meant? (Well, okay, probably not that many since it’s never exactly been a best-seller.) As readers we’re used to assessing the quality of the text in front of us, whether Wikipedia entry, newspaper article, or scholarly tome, but it’s sometimes harder to decide whether an edition is a faithful representation of the original text or not, especially if you’re just dipping into it. Of course we can’t all go rushing off to the manuscript whenever we spot something unlikely in a printed text but if it’s the crux of your argument then it’s worth having a look.

While I’m on the subject I should add that going back to the original manuscript doesn’t just allow you to spot errors like this one, or omissions. A printed page, with its neat rows of type, each letter formed in exactly the same way, can never convey as much information as the manuscript. I always feel as though I know an author better when I’ve seen his work written in his own hand. Hooke’s meandering lines of tiny script with their many insertions of extra text squeezed in above a line tell, better than anything else, that he didn’t plan on other people reading his diary. All the more important to get the printed version right!

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!

The lives of others

Robert Hooke FRS started writing his ‘Memoranda’, as he called his daily entries, on 10 March 1672. There’s no clear statement about why he started this project, just the terse entry ‘Memoranda begun’, followed by some characteristically abrupt notes about the weather and so on. It’s worth reproducing the whole of his first entry here:

Sun. 10 [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.

I told Cox how to make Reflex glasses by Silver and hinted to him making them by printing. Hewet brought me £10 from Brother John Hooke. News of 3 empty Dutch ships taken by ye montacu frigat

Despite Hooke’s lack of explanation about his motivation, I think this entry is revealing. His weather notes and barometric readings  were part of a long-running project to investigate the weather with a view to predicting it in advance. He kept these records as part of his memoranda for over a year, but then stopped (maybe he started recording them elsewhere). At the same time, his first entry signals other reasons for keeping a record of his activities. He noted a conversation with Christopher Cox, a scientific instrument maker; a financial transaction; and a piece of news. Throughout the diary these types of records come up again and again, and I think this is why he began with the word ‘memoranda’ – that is, things to remember. The diary is primarily a record of Hooke’s daily transactions during an incredibly busy period of his life, when he was surveying London building sites, designing instruments, doing experiments, lecturing, catching up on the news at coffeehouses, meeting friends, arguing with his maid, trying out new medicinal preparations, buying books, and occasionally getting paid for his work. It’s no wonder he felt that he needed some way to keep track of things.

This is emphatically not a diary written for others to read. It’s a raw account of everyday life in Restoration London, including the mundane and repetitive. It’s often incomprehensible unless you have some idea of what’s going on – who Hooke is meeting and why. I’ve embarked on the project of re-editing it primarily because I want more people to be able to read and understand it so they can get to know Hooke and his world for themselves. I don’t have all the answers yet by any means, but this blog will be a way of sharing my adventures in Hooke’s London (and maybe getting some advice from readers who know more than me about various things!).