brilliant, almost other-worldly discoverers and inventors. To some extent these changes are
reflected in the emergence of “popular” science literature in the 19th century, ‘s Gravesande
on the other hand wrote a book on Newtonian mechanics, Physices dementa mathematica,
which circulated widely amongst fellow researchers and amateurs interested in Newton’s new
philosophy.
So, what, apart from the fact that he started acquiring models for Teylers Museum’s
collection, supports the idea that van Marum was trying to establish himself as a popular
lecturer? Recall, for instance, that he had first built a reputation in Haarlem as a town lecturer.
What’s more, the acquisition plan he submitted to the trustees contained a direct reference to
s Gravesande, in that van Marum wanted to use the Newtonian’s famous book containing
descriptions of devices to demonstrate the laws of mechanics as a blueprint from which to
select the models to be purchased for the museum.47 Finally, van Marum had himself started
giving a series of lectures on his research in the Foundation’s name shortly before submitting
this plan: in 1786, he first gave lectures on his research on the geological collection before
members of the Second Society. After 1790, his audience included the trustees of the Teyler
Foundation. By this time, he had broadened the scope of his lectures to include chemistry, not
just geology. His lecturing culminated in a series of lectures before a far larger, general
audience between 1795 and 1797. This was after the French Revolutionary Army had
occupied the Netherlands, bringing with it a greater appreciation of the common “citoyen”, at
least rhetorically. In how far van Marum giving these particular lectures for a general
audience was part of a cunning attempt on his part to gain favour with the new government is
debatable. He certainly did not have to betray any of his principles in order to give the
lecturers.
In fact, this is something that needs to be stressed: even though the preceding summary of van
Marum’s actions and ideas has been phrased largely in strategic terms and the focus lay on
what was at stake for him personally, throughout his life van Marum always displayed a
genuine, altruistic desire to pass on and spread whatever knowledge he had gained. This, as
much as anything else, will undeniably have motivated him to acquire other instruments for
the museum besides those he could use solely for research purposes.
There is one final point that supports the notion that van Marum saw himself as accepting
some kind of baton that was handed down from earlier diffusors of knowledge such itinerant
lecturers like Fahrenheit: his exquisite acquisition plan prompted him to go on a trip to
London. At the time, the British capital was still the centre of the instrument making world,
which was the main reason van Marum travelled there.48 But in doing so he was also
emulating generations of Dutch Newtonians. As has been pointed out by Trevor Levere,
travelling to London was “in line both with Van Marum’s own ambitions, and with the great
tradition of experimental Dutch Newtonians”.49 ‘s Gravesande himself had become an
48Ibid' On London’s status as instrument making capital o f the world see for instance: Jim Bennett, “Instrument
Makers and the ‘Decline o f Science’ in England: The Effects o f Institutional Change on the Élite Makers o f the
Early Nineteenth Century,” in Nineteenth-century Scientific Instruments and Their Makers, ed. Peter R. de
Clercq (Amsterdam: Rodopi, 1985), 13.
Levere, “Teyler’s Museum,” 53.
adherent to Newtonian mechanics during a sojourn in London. And, in a way that affected van
Marum on a more immediate level, his mentor Petrus Camper had recently travelled to Britain
as well.50 He was therefore able to provide his former pupil with letters of introduction, even
though by this time the name van Marum was not unknown across the channel. Jan
Ingenhousz, residing in Britain at the time, had suggested the trip and chaperoned van Marum
during the first few days of his visit to London. Van Marum had also corresponded with
notable British instrument makers and chemists such as Joseph Priestley on a range of issues.
At one point his activities had led to a public disagreement with Henry Cavendish, which in
turn was one of the main reasons van Marum was only elected to the coveted membership of
the Royal Society some eight years after his visit to the illustrious institution.51
The trustees not only supported this trip of van Marum’s, but actually paid for it too. This
goes to show that they were willing to go to great lengths in supporting van Mamm’s
activities. In his acquisition plan drawn up in 1789, van Marum had summarised:
“According to this plan Teylers Museum should be able to acquire a Cabinet of Physical and
Mechanical Instruments, that has no equal in our country, and that is, as far as we know, also
unparalleled in other countries.”52
He was serious. And so - evidently - were the trustees in supporting this aim.
9. London and the Aftermath
In July 1790, van Marum thus left for England, “in order to set up permanent contacts there so
as to acquire such machines as cannot easily or so well be obtained in this country at the
moment”, as the trustees’ summary of his plans reads.53 What they didn’t mention in the
minutes of their meetings, but must have been discussed as well, was van Marum’s plan of
finding an instrument maker who could be employed by the Teyler Foundation and assist him
in Haarlem, an idea which the trustees supported.
Interestingly, it was once again van Zeebergh who emerged as van Marum’s principal contact
and champion amongst the trustees. Although van Marum was permitted to acquire
50 Ibid., 63.
51 On van Marum’s campaign to be elected and the difficulties he encountered see: Trevor H. Levere, ‘T h e
Royal Society o f London,” vol. 3, Martinus van Marum: Life & Work (Haarlem: Tjeenk Willink & Zoon, 1971),
33-40.
52 “Volgens dit plan zoude men in Teylers Museum een Cabinet van Physische en Mechanische Instrumenten
kunnen verkrijgen, zo als er niet alleen in ons land geen bekend is, maar waar van ook zo ver wij onderricht zijn,
in andere landen geen gelijksoortig schijnt gevonden te worden.” “Beredeneerd Plan voor het aanleggen van een
Cabinet van Physische en Mechanische Instrumenten in Teyler’s Museum”, c. 06.1789, Haarlem, NHA, Archief
van Marum, vol. 529, nr. 9.
53 “ten einde aldaar eene vaste correspodentie op te rigten om zodanige Werktuigen welke thans hier te Lande
niet gemaklijk o f niet zo goed te bekomen zijn, te verkrijgen” ; “Directienotulen”, 18.06.1790, Hartem, ATS, vol.
5.