Observation and experiment were central to the practice of eighteenth-century scientific enquiry and both activities relied on sensory experience as a means of acquiring knowledge and as a form of knowledge in itself.¹ Of course, much of this period’s investigative ethos relied on intellectual and practice-based developments made in the previous century, under the banner of the ‘new science’ and, by the 1700s, experience had become a primary method of examination. Whereas medieval thinkers saw personal experience as a way of observing how the world was, for eighteenth-century enquiry – it was a method of analysis. Or, as Francis Bacon had put it, of ‘vexing’ nature into revealing her secrets.² As such, scientific observation has a very long history and can be considered as the sensory technology capable of converting experience into knowledge: ‘the most pervasive and fundamental practice of all the modern sciences’.³ For the people explored in this book, the ways in which experience developed through domestic practice was converted into evidence require further examination.

Despite their joint reliance on experience, observation and experiment were defined in ‘contradistinction to one another’ by nineteenth- and twentieth-century scientists and thinkers. This led to an under-appreciation of observation in histories of early modern science.⁴ Moreover, experiment has been conceptualised as active and embodied in contrast with passive or uncritical observation. This chapter discusses examples of observation and the following chapter will consider experimental activities. However, these practices often acted as two sides of the same coin and were strongly connected within print culture, with publication titles often including both.⁵ Many of the individuals examined here were engaged in both observation and experiment. Here, a central case study is used to examine observation as it took place in the homes and lives of two Dublin apprentices who observed the skies in their pursuit of astronomical skill and knowledge.

Paying attention

As Lorraine Daston has emphasised, for eighteenth-century naturalists, ‘observation was first and foremost an exercise of attention’.⁶ By way of preface to this chapter’s main case study, it is worth briefly considering a more famous contemporary example. In the scholarship on natural historical observation, the Hampshire-born and based cleric and diarist, Gilbert White (1720–93), is a major figure. In part, this prominence is due to the role played by White’s research in laying the foundations for nineteenth-century naturalists, notably Charles Darwin, to make their famous interventions. However, the longevity of his reputation is also attributable to the ‘clarity with which he showed the importance of appreciating not only the kind of attention an object invites but also the manner most appropriate for expressing what is observed’.⁷ Like other naturalists of this era, White subscribed to a model of information gathering that was intensely local, best articulated in his major work, Natural history and antiquities of Selbourne (1789), seeing himself as one part of a much larger, collective project of empirical research. As indicated in Chapter 2, the relationship between observation and record-keeping was a close one. Regular observers of natural phenomena might take their notes in pen and ink, but such observations also formed a core part of the published compilations of learned societies. As the next two chapters of this book show, contributors of such observations to both societies and a vibrant periodical press were diverse and drawn broadly from society at large.

White conformed to one of several common models of the ‘man of science’. An Oxford-educated member of the lower gentry, his father had been a barrister and his grandfather the vicar of Selbourne. Whilst White did not enjoy the freedom over his time of the wealthier landed gentry and aristocracy, his comfortable existence and educational and professional connections smoothed his path to enquiry. White’s personal delight in observing nature is present in his text and readers, over many centuries, have been drawn to the immediacy of his descriptions. During his lifetime, White took on a range of curacies in Hampshire and Wiltshire, alongside the offices of Junior Proctor and Dean at the University of Oxford. At the end of his life, White had assumed both his grandfather’s role and home as the curate of Selbourne living at The Wakes vicarage.

For the purposes of this chapter, there are several features of White’s scientific work that are interesting. Firstly, his descriptive writing not only taught others how to observe nature, but also expressed the excitement that could be generated by this process – even when applied to the familiar contours of a local neighbourhood. His work is an articulation of how careful record-keeping based on personal observation could offer a route to distinguishing truth from superstition.⁸ However, in this search for observable fact, White did not discard the valuable evidence of traditional belief and anecdote. In a section on the decline of certain types of game and, in particular, the red deer, White relied on the testimony of ‘an old keeper, now alive, named Adams, whose great grandfather … grandfather, father and self, enjoyed the head keepership of Wolmer forest in succession for more than an hundred years’.⁹ Similarly, his observations on the presence of bog oak in the south of England rested on the assurances of ‘Old people’ who ‘have discovered these trees, in the bogs, by the hoar frost, which lay longer over the space where they were concealed, than on the surrounding morass’.¹⁰

The centrality of a range of practices associated with scientific observation (live sightings of natural phenomena, detailed record-keeping and wider information gathering and exchange) combined with engaging prose, ensured a readership for White’s work. However, behind his famous Natural history sat a range of journal-keeping and correspondence (the latter reproduced or re-imagined as the basis of that publication). As mentioned in Chapter 2, a version of White’s weather diary was published in the Gentleman’s Magazine, thereby dramatically increasing the reach of his writing and feeding into a print culture that was familiar and accessible to very many eighteenth-century people.

The second dimension of White’s work that resonates with the findings of this book is the evocation of sensory experience in his descriptions of wildlife. White’s approach differed from natural histories that prioritised sight as a primary sense ‘in taxonomic descriptions’, making clear instead the importance of a range of senses in observation, his narrative including ‘vivid accounts of rancid-smelling bats, stinking snakes, the putrid stench of death, and the sulphurous smell of a blue mist that heralds a thunderstorm’. Likewise, he observed the importance of song in identifying species of bird and the way certain geographical features generate echoes.¹¹ This attendance to the sensory, both the observed senses of fauna and also the sensory perception of the observer, is a feature of the domestic silkworm breeding discussed in detail in the next chapter.

Finally, despite White’s privilege in terms of his access to the resources and networks of institutionalised intellectual life, he still emphasised the accessibility of discovery to ordinary people. His characterisation of the everyday as exotic and mysterious established a context and a motivation for enquiry that many less materially fortunate individuals could relate to and replicate. The value of repetition for the observer of nature was obvious in his work, and rhythms of repeated return to the same objects of enquiry were reflected in the characteristics of many domestic tasks.¹² The practices at the heart of White’s naturalism may have been commonplace in this period, but his writing did create a vivid and alluring rationale for the active participation of others in this inherently collective project.¹³

Observing the skies

At first glance, astronomy might be judged an inaccessible science on account of its use of expensive instruments and prerequisite mathematical ability. However, as discussed in Chapter 3, astronomy in Britain thrived outside of the formal institutions of learning and science with participation from many ‘amateurs’. Whilst England had the Royal Observatory at Greenwich and Ireland boasted three major observatories in Armagh, Birr Castle and Dunsink, institutionalised astronomy was mainly focused on supplying navigational data or developing the mathematical facet of the field.¹⁴ This left the field of practical research wide open to the interested individual. Moreover, astronomy, from its earliest origins, was a field of enquiry integrally connected with observation and also with one of the key instruments of such, the telescope. From the mid-eighteenth century onwards, there was a rapid increase in understanding of the universe, including the identification of new planets, planetary satellites and asteroids. There was an eager public audience engaged with these celestial discoveries, with travelling lecturers offering talks and courses and publishing prolifically on the subject.

The practicalities of engaging with astronomy depended to some extent on the nature of the science itself. As Peter Dear has highlighted, ‘there was no formal methodological separation between observational and the calculational parts’ of astronomy, and astronomers were in the habit of turning their own observations into predictive tables and models of celestial movements as a prerequisite for sharing their findings with a wider audience.¹⁵ So, on the one hand, the singular nature of astronomical observation – requiring the observer(s) to be in situ, with the correct equipment at a particular time – denied the possibility of easily, publicly demonstrable observations and experiments as were typical in other fields. However, on the other hand, the proliferation of astronomical observations, calculations and predictions in cheap print made this sphere of enquiry surprisingly open to popular participation.

The close relationship between print and astronomical activity was manifold. In particular, the potential for predicting the future made celestial modelling extremely attractive to a variety of people for a range of purposes. In fact, astrologers relied upon astronomical data to make their popular forecasts – whether that was for the weather, the harvest, matters of health or political ferment. Many famous astronomers of the period had a firm interest and belief in the astrological ramifications of their own observations and calculations.¹⁶ Prior to seventeenth-century developments in the scientific method, astrology was considered to be a systematic and ‘scientific’ endeavour and astrologers made large claims for their science’s ability to explain the natural world and its effects.¹⁷ As discussed in Chapter 2, Isaac Butler saw the weather as integrally connected with celestial phenomena and he was personally involved in the compiling of astrological almanacs. Of course, early modern people were very invested in astrology, as the ability to predict natural phenomena was of critical value to anyone who farmed, fished or raised livestock and many more besides. The strong connections between astrology and religious belief, medical treatment and the analysis of society and politics gave this field unparalleled inroads into people’s daily lives and worldviews.

Almanacs were the publications that capitalised most effectively on the popularity of astrological reasoning, and in the early seventeenth century, they were likely the largest category of print culture – sold to a truly mass audience.¹⁸ By the mid-eighteenth century, the almanac had passed its peak; however, there remained widespread popular and scholarly belief in astrology and a large readership for this kind of cheap print publication. In the sixteenth and seventeenth centuries, the Irish print trade had been tightly controlled as compared to the British business. However, by the turn of the century, Dublin had begun to emerge from the absolute control of restrictive patents, thereby allowing the book trade to expand. Despite a very large population of Irish speakers in the country in this period, printing was predominantly in English which was the main language of administration and business in Ireland.¹⁹ This chapter reveals the extent to which lower-status astronomers relied on this format to establish and advance their own observations and calculations.

However, the traditional annual almanac was not the only category of publication that helped its readers build their astronomical skills. Mathematical problem-solving was a mainstay of long-running journals. For example, the Ladies’ Diary or Woman’s Almanack which ran from 1704 until 1840 had to remove recipes and other forms of content to make room for mathematical challenges. This publication was not only one of the earliest periodicals aimed at a female readership, but it was also the first of its kind to provide a public forum for mathematical exchange.²⁰ Explicitly instructional texts, such as manuals, offered their more specialised readerships the option to assemble instruments for use in astronomical calculation. In this way, the readers of an earlier generation of instructional text – John Blagrave’s Mathematical jewel (1585) – could learn by cutting out pre-prepared templates, glueing them onto board and constructing a usable device. This complicates understandings of ways of knowing that primarily rest on sight, text and reading and those that rely on material literacy, physical manipulation and embodied knowledge.²¹ However, these different forms of print culture also reveal a wide and diverse audience for mathematics and, with it, the seedbed for ‘amateur’ astronomers not only to follow but also to participate in the frenzy of celestial discoveries that took place in the later eighteenth century.

Two such enthusiasts were the young Quakers, Robert Jackson (1748–93) and Thomas Chandlee (dates unknown), both apprentices living in Dublin in the late 1760s. The evidence of their endeavours is contained in correspondence held at the Friends Historical Library in Dublin. Only Jackson’s letters survive, and at this time he was a twenty-year-old apprentice to his father, the printer and publisher Isaac Jackson of The Globe, Meath Street in Dublin who was also an official printer for the Quakers.²² The letters were written over the period 1768–69 and document Jackson’s role as tutor to Chandlee on matters of astronomy. Chandlee was the son of merchant Thomas Chandlee senior of Athy in County Kildare, but he was apprenticed to Robert Fayle, a linen draper in Bride Street – just a few streets away from Jackson’s place of residence and work. Jackson completed his seven-year apprenticeship in March 1769 and began work as a journeyman.²³

These were a pair of young men, working hard to establish themselves within a trade and living in houses with their master, his family, other apprentices and most probably servants. At the time of Robert Jackson’s apprenticeship, his father also oversaw the work of Thomas Byrne (either as an apprentice or a journeyman) and another apprentice who absconded after five years of service.²⁴ Clearly apprenticeship did not always suit Chandlee, as Jackson reprimanded him in April 1769: ‘I do not approve of thy calling apprenticeship, slavery; perhaps thou wilt not consider how happy thou hast been ‘till thou hast much more care upon thy head.’²⁵ Besides their shared experiences as emerging tradesmen, the letters demonstrate a detailed knowledge of astronomy and the ability to make calculations concerning the position of celestial bodies. They also cast light on networks of exchange facilitated by the periodical press in this period. Given his trade, Jackson had a particularly detailed grasp of the market for periodicals and good access to a wide range of these publications.²⁶ Together, these facets of the correspondence are revealing about eighteenth-century urban, intellectual culture.

Some of Jackson’s letters include the workings out of specific calculations, presumably for Chandlee to model, and also comparisons of other astronomers’ reckonings and published figures. Typically, the letters are written conversationally but, occasionally, Jackson moves into a more didactic style, running through a particular concept or calculation for Chandlee. Jackson often signed himself ‘Philalithes Astronomus’, meaning lover of astronomical truth or, simply, ‘Philalithes’.²⁷

The letters also include comments on reading and updates on Quaker meetings, and Jackson would add jokes, riddles or aphorisms at the top of the page, designed to amuse. For example, in May 1769, this reassuring message appeared:

Occasionally, small diagrams would appear, such as the example from June 1769 shown in Figure 4.1.

Figure 4.1 ‘Types of the Solar Eclipse’, Robert Jackson, 4 June 1769. All rights reserved and permission to use the figure must be obtained from the copyright holder.

Whilst the balance of subjects varies letter to letter, astronomy certainly takes the lion’s share of the page, with Jackson commenting in the summer of 1769, ‘But Astronomical Matters are finished, they having very well fill’d up my epistle, which otherwise would have been but short, for want of something requiring answers in thine, or other entertaining matter in mine.’²⁹ Thomas Chandlee was not Jackson’s only student, although Jackson credited Chandlee with encouraging his own astronomical investigations and claimed to ‘take more pains with thee then any other of my pupils’.³⁰ Despite the teacher–student relationship, Jackson fostered Chandlee’s independence and even disavowed the need for a tutor in this field of enquiry:

In 1768, a letter noted Jackson’s approval of Chandlee’s progress – ‘Thus I have finished my instruction astronomical, by aquainting thee with Parralexes’ – and declared Chandlee no longer a scholar ‘but a tyro [novice] astronomer’.³² Jackson also noted Chandlee’s superior eyesight and ability to distinguish objects at a greater distance than himself – suggesting, modestly, that Chandlee was in fact the better astronomer.³³ He even addressed letters to ‘T. Chandlee, Bridestreet Astronomer-Royal’, drawing his friend into a tongue-in-cheek aggrandisement of their shared endeavour.³⁴ Nevertheless, throughout this correspondence, Jackson posed questions to Chandlee – testing his capacities of observation and calculation – and expected them answered by return of mail.

Astronomy on a shoestring

It is tempting to imagine that only the deep pockets of wealthy landed gentlemen or aristocrats could give rise to the extensive use and regular adaptation of domestic space for intellectual work, but this was not the case. Similar practices, on a more modest scale, are visible in the correspondence of Jackson and Chandlee. Both young men lived in relatively limited domestic space, further compromised by the presence of other people. Their time was dominated by the demands of their respective apprenticeships. Despite these hindrances, they found room for their favourite occupation.

Robert Jackson lived in his father’s premises – a house and shop – alongside other apprentices. In these busy surroundings, he was able to make himself a small study space that he referred to as the ‘Hygrometer closet’ on account of its containing such an instrument.³⁵ Jackson made active use of the space available; for example, he described two methods for making a meridian line, one of which used the shadows cast by a casement window on the floor of a room.³⁶ Another letter speaks to the chance sightings possible within even confined domestic space, as Jackson mentions seeing Saturn as he was going upstairs on 3 December 1769.³⁷ On occasion, to gain an improved view of the ‘Western side’, Jackson craned out of a ‘back Garrett window’, which he described as ‘my best Uraniburg’ in reference to the sixteenth-century Danish observatory of the same name.³⁸ Regular notes appear in these letters about the specifics of views possible from, often, the top windows in their respective city homes. One evening, Jackson enquired, ‘Hast thou seen lucida lyra peeping late over the houses (not yet to be seen from the street but from a window) towards the N. East?’³⁹ This example shows that eighteenth-century investigators used their homes flexibly, pushing their spatial and material affordances to accommodate a wide range of activity, even when other members of their household had different designs on the space.

Another major obstacle to scientific enquiry was the lack of access to reliable instruments of measurement. However, astronomy could be undertaken with a few basics or the possibility of borrowing a friend’s apparatus. By and large, Jackson’s access to suitable equipment and space for this pursuit out-stripped Chandlee’s, but he was often generous with his resources. In November 1768, Jackson offered to lend Chandlee his quadrant, an instrument capable of measuring altitude.⁴⁰ However, Jackson stressed that to make use of the gadget, Chandlee would need to be shown how to operate it in person, emphasising the relevance of embodied knowledge.⁴¹ A year later, Jackson suggested Chandlee might borrow his pocket quadrant to enable measurements on the hoof, and he asked that his friend use a watch to note the time of the sighting and report these and other relevant details back, allowing Jackson to discover which precise star he had seen.⁴² Despite the centrality of the telescope to astronomy in this period, ‘it by no means displaced sextants and quadrants’ and ‘telescopic sights’, the latter ‘arguably contributing more to astronomical observations’ than the telescope at this time.⁴³

Less easy-to-loan items were still made available to others, as Jackson hoped ‘soon to have the hygrometer ready for your inspection & Isaac’s or Thomas’s if I could catch him at some conven[ien]t time’.⁴⁴ In December 1769, Jackson wrote to say that he had made Chandlee a pocket calendar designed for astronomical annotations and notes.⁴⁵ In another letter, Jackson described – for Chandlee’s benefit – his own approach to annotating almanacs with observations.⁴⁶ These examples, including a homemade note-keeping technology, underline the prevalence of record-keeping practices in manuscript, print and hybrid formats discussed in Chapter 2.

As described, these young men lived in busy households. Their references to garret windows, attic spaces and closets signify the position of their own sleeping quarters in the least salubrious parts of the home. However, Jackson had access to another more specialised space for studying the skies – Crumlin House – which he described as a ‘lodging’ and ‘a convenient empty house of 5 or 6 rooms’.⁴⁷ This site was located about two miles southwest of Dublin and was made available to a group of astronomers for making observations. On 7 August 1769, Jackson reported there being ‘4 folks’ who ‘lie [here] … every night as yet, of which 2, and I one of the 2; depart every morning, & return in the Evening’.⁴⁸ Jackson’s use of Crumlin House certainly served his purposes. In a letter written partly at Crumlin and partly at Meath Street he recalled a series of sightings: ‘At Crumlin one night since my last, I saw Charleswain, Arcturus, 2 shoulders of Auriga, Bootes, the Polestar, most of Swan … Lyra, almost all the Dragon & Cassiopeids Chair.’⁴⁹ Jackson had also seen ‘Caroli between the horizon & the last star of the Bear’s tail’ but failed to glimpse ‘Spica’, ‘Antares, Mars, the Pleiades’ and Venus.⁵⁰ As these observations suggest, the apprentices were attempting to gain sight of some of the brighter stars and planets in the sky, and to identify key constellations.

No doubt, Crumlin House’s location outside of the city reduced some of the interference from residual urban light and thereby increased the likelihood of a clear sighting. Jackson referred to the difficulty of seeing clearly in the city in a letter written on 12 August 1769: ‘I understand thou art by this time in town again; I have not much to write about now, What observations hast thou made in a place where the smoky Canopy of Dublin could not dim the stars to thy view?’⁵¹ One letter, addressing Chandlee as ‘Astro Professor’, referred to a star being ‘visible from thy observatory’ meaning Chandlee’s home in Bride Street, but obscured from his vantage point in Crumlin House: ‘I can’t expect well to see him, the southern part of my horizon is so encumber’d with a steeple, trees &c. I have a better chance to see him from Meath Street.’⁵² A postscript on the same letter revealed Jackson back in situ in the Meath Street hygrometer closet, perhaps hoping for a glimpse.⁵³ However, for largely superior views of the night sky, Jackson made the journey on foot between Meath Street and Crumlin regularly, each leg taking him ‘42, 43 or 44 minutes’.⁵⁴ This comment speaks to Jackson’s inclination for taking repeated measurements with his watch, but also to the importance of slivers of time that could be used as he pleased.

Although it was Jackson alone who had ongoing access to Crumlin House, he revealed the urge to share this with Chandlee when he wrote, ‘I want thee at Crumlin to see the Garden … I was thinking if we could appoint some time, suppose 1st day evening to meet ab[ou]t 6 and walk thither. Fine views of the milky way now at night at Crumlin.’⁵⁵ Jackson’s use of an alternative space for astronomical observation was unusual; most working people who were curious about the natural world had to conduct their investigations within the spaces of home. Moreover, domestic spaces for scientific enquiry were often plagued by disruptions; Jackson reported on 22 October 1768 that ‘all things (the hygrometer and a few others excepted) have been turned out of the Hygrometer closet & the room adjacent. My ill-looking desk was whirled into the dining lumber room, from whence I now write.’⁵⁶ Nonetheless, the home re-imagined as an observatory and pushed to the limits of its spatial affordance was where Jackson and Chandlee set to in their mutual investigation of the night sky.

A community of astronomers

In May 1769, Jackson wrote to Chandlee to ask, ‘Hast thou observed a star not far west of Jupiter called the South Balance, and over him (Jupiter) another in the middle of the beam, both these bright stars of the 2nd magnitude – about 2 hours after Jupiter rises Antares[?]’⁵⁷ In this way, the letter-writers exchanged details of their independent observations, sharing in the excitement of sightings together. However, these apprentices were in touch with a network of other astronomers across the city, and aware of a broader community of star-gazers – including famous individuals – through their reading of periodical literature. For example, on 17 April 1768, Jackson commented, ‘The Empress of Russia & her astronomers are ab[ou]t preparing to observe the transit of venus, tho’ so far off, as 6th mo. [June] 1769.’⁵⁸ On 22 October of that same year, Jackson discussed astronomers including Charles Leadbetter (1681–1744), in particular his Table of Eclipses for the years 1724–40.⁵⁹ Another letter gossiped about a disagreement between fellow Dublin star-gazers:

These comments illuminate several characteristics of Jackson’s engagement with astronomy. Much as he used a pseudonym – ‘Philalithes Astronomus’ – inspired by Ancient Greek, the use of Latin words to describe local contacts signalled a familiarity with Classical languages, if only a passing one. Certainly, the humorous performance of his own role of teacher in his friendship with Chandlee seems a more likely motivation than the maintenance of the anonymity of a neighbourhood shoe-maker and teacher. This letter also underlines the inclusive nature of astronomical enquiry, encompassing tradespeople and professionals and, in this case, people known to Jackson personally or by reputation. The shoemaker’s address was most likely on the northern end of modern-day South Great George Street, next to Dublin Castle, whereas the teacher lived in the same street as Jackson – part of the Liberties, an area with a thriving textile industry at its peak in the late eighteenth-century city. The fact the disagreement was settled by consulting an ‘ephemeris’ – a table providing details of the positions of planets and stars over a period of time – emphasises the centrality of print culture in enabling ‘amateur’ astronomy at this time.

These letters also document regular meetings of like-minded acquaintances on St Stephen’s Green to observe the stars. In one letter, Jackson described doing so early in the morning before he started the day’s work and, in another, he declared the season too cold and himself too busy for such a rendezvous with Chandlee.⁶² On 7 June 1769, Jackson wrote warmly to his ‘Loving Correspondent’ to report an exchange between himself and two other astronomers: ‘Hutchinson communicated to me his Observations on the Eclipse, which were much preferable to either Harding’s or mine.’⁶³ Hutchinson earns several mentions in these letters, sometimes referred to as the ‘astronomer of High Street’⁶⁴ and also as Jackson’s ‘astro brother’.⁶⁵ However, a decent timepiece had aided Hutchinson’s measurements:

By collecting this information from a range of independent viewers, Jackson was able to critique the calculations printed in periodicals: ‘I think many of the Almanack writers were much mistaken about it’; one ‘made the Digits somewhat too small’ and another ‘erred in making the duration near 10 min too much’.⁶⁷

In June 1769, Jackson commented on another discrepancy between the calculations of Dublin-based astronomers, which had taken place several decades ago: ‘but this is but very little in comparison of what happened in 1737, when T. Hutchinson observ’d the great solar eclipse and found it to differ 28 min from the Calculation of an Astronomer that lived not many miles from Chequer lane’.⁶⁸ Later that year, Jackson noted further criticisms of the astronomical content in Watson’s Dublin almanac.⁶⁹ In these comments, it is also clear that Jackson was not only concerned with current or very recent astronomical activity but tracked back decades to understand the context for his own activities and those of other astronomers, famous or otherwise.⁷⁰ This concern with the long-term was characteristic of astronomy, which relied on centuries-old record-keeping to determine celestial cycles.⁷¹

On 7 June 1769, Jackson wrote to Chandlee concerning a partial eclipse of the sun that had occurred first thing on the morning of Sunday 4 June and also a transit of Venus that had taken place over 3–4 June. The latter represented an important step forward in human understanding of the universe because both the 1761 and 1769 transits of Venus (witnessed as a small black disc travelling across the surface of the sun) offered astronomers across the globe the opportunity to make measurements that, taken together, could confirm an accurate distance between the earth and the sun. Jackson communicated a range of sightings from among his network, including an R. Blood and John Wilcox seeing the transit ‘with prospect glasses’, one from ‘Clibborn’s terrace’, which likely referred to a property in Banbridge, Co. Down, owned by the Quaker Clibborn family, and the other from ‘the bank house’.⁷² However, ‘the most curious observation on the transit was made by a lad of my acquaintance in Meath Street; who with (I suppose) a very bad piece of glass smoked, saith he saw something very near the sun, with a tail to it’.⁷³

Jackson was also keen to hear more about the company Chandlee was in when he ‘led [them] forth into the Park to observe the eclipse’.⁷⁴ The urgency of capturing as much information as possible about the eclipse rested on its relative rarity: ‘We had never a visible eclipse of the sun since 1766 to this late one, and I imagine we will not see another at least these two years.’⁷⁵ Jackson seemed disappointed with the limited use Chandlee had made of this unusual opportunity, remarking, ‘I think if thou hadst been diligent thou might have found the duration to less than a minute.’ However, he had to recognise the constraints of Chandlee’s setup, acknowledging that ‘the help of my mock telescope’ might have made such a calculation more possible.⁷⁶ Whilst Jackson could not afford the expense of an instrument-maker’s telescope, this reference to a ‘mock telescope’ suggests he had constructed something himself to approximate the effect. This interpretation is underlined by a comment in another letter:

Not only were some of Jackson and Chandlee’s tools homemade, but they were also incomplete or failing. Nevertheless, the correspondence shows a determination to continue regardless and to incorporate the fallibility of the instruments – their own and other people’s – into the analysis of what had been seen and, therefore, what could be known. However, this zeal was notably absent in other members of Jackson’s household, as he mentioned ‘Many lay in bed and saw not the Eclipse’; besides himself, only one other member of the Meath Street house witnessed the phenomenon: ‘thus laziness hindred many of seeing what I think deserved notice’.⁷⁸ Before concluding his letter, Jackson commented, ‘The Crumlin House was admirably well situated for observing the transit, but to my regret not so for the eclipse, for seeing which the Meath Street house was tolerably well situated.’⁷⁹

These two intense years of apprenticeship and astronomy came to a close in 1769, when – ahead of Chandlee – Jackson’s indenture expired and he became a journeyman. In a letter dated 23 April 1769, Jackson reported tidying up the house before his departure: ‘last week & this week, house & shop to be brushed up and put in order, so I have something to do but that is not wonderfull as it is the Case every week’.⁸⁰ However, he could not end the letter without a brief comment on the stars and an offer of help: ‘Mars has now got as far as Castor’s foot – will not the representation of nocturnal appearance of 5 mo. 1st [1 May], be soon of use to thee?’⁸¹ Then Jackson signed off: ‘Farewell, I remain thy Wellwisher and old Acquaintance, Astronomus.’⁸²

It seems certain Jackson and Chandlee remained in touch thereafter, but this period of regular corresponding casts light on the incredible curiosity of both men and the determination with which they developed their interest in astronomy and the skills they could bring to bear in both calculation and observation. It is worth noting that through this period of frequent letter exchange, the men also had the opportunity to meet in person – to confer on the particulars of a given exercise or to make a sighting together, alongside others of their local acquaintance, on St Stephen’s Green. Despite substandard instruments and a heavy daily workload that took them away from their windows and periodicals, the depth of engagement was significant – their knowledge was considerable.

Conclusion

Here, Jackson and Chandlee can be seen to illuminate important features of the culture of curiosity in this period, despite occupying marginal positions in relation to the institutions and high-profile personalities of Enlightenment science. It is also worth noting that regardless of the vast disparities in financial resources, domestic space and family connections that existed between the working men in this chapter and Lady Clive, discussed in Chapter 3, their level of engagement was not dissimilar. Both apprentice and aristocrat struggled to see some celestial bodies through the instruments at their disposal, they both relied upon published tables and print culture to compare and contrast findings and, in each case, the corroboratory information made possible by networks of astronomers, from many walks of life, fuelled their enquiries.

The testimony of Jackson’s letters brings themes to the fore that are important for a full understanding of the experience and practice of ‘science’ in eighteenth-century Ireland and Britain. Ursula Klein has identified ‘bodily skills to connoisseurship of materials, tacit and verbal to articulated know-how, to methods of measuring, data gathering, and classification’, analysis and representation as important skills and knowledge for eighteenth-century scientists – all of these qualities and activities can be seen at work in the letters discussed here.⁸³ Likewise, as Daston has also characterised for virtuosi, scientific observation for Jackson and Chandlee regulated their lives, from the routes they walked across the city, to the repeated cycles of observation, calculation, reference and comparison. Astronomy also shaped these men’s social lives and networks of association.⁸⁴ Their letters offer a glimpse into tradespeople’s households and the ways in which these spaces and their regimes of labour drove and shaped enquiry.