Visited Christiaan Huygens in Den Haag with the Durven brothers
On June 19, 1684, Christiaan Huygens wrote to his father from Den Haag:
L'autre jour le Sr. Leeuwenhoeck avec les deux frères van Durven furent icy pour voir, quoque de jour, notre maniere d'onserver, ne l'ayant pas pu comprendre assez par la description que j'ay donnée. Je regarda le Soleil et y trouvay par hazard quelques tasches assez remarquables, mais l'air etoit trouble quoyque clair, ce qui fit qu'on les voioit pas ien distinctement. Ils furent fort satisfaits de la nouvelle invention. Je leur demanday pourquo ils n'avoient point aporté ce vere de 30 pieds, et comment ils l'avoient eprouvè. il me dirent que ce n'voit ate que dans une chambre beaucoup moins longue que de 30 pieds, mais que jusques la ou ils avoient pu se mettre, on regardant les objects encor droits en debout, il avoit paru bon.
The other day Sr. Leeuwenhoeck with the two brothers van Durven were here to see, day by day, our way of observing, not having been able to understand it enough by the description that I gave. I looked at the sun, and found by chance some rather remarkable heaps, but the air was so slightly clear that they were not distinctly visible. They were very satisfied with the new invention. I asked them why they had not brought this 30-foot glass, and how they had tested it. they told me that it was only in a room much shorter than 30 feet, but that even where they had been able to put themselves on, while looking at the objects still standing upright, he had looked good.
That would have been Paul Durven and his older brother Gerard, a surgeon in Delft.
A week later, Huygens followed up in another letter to his father:
Je feray bien aise d'apprendre ce que vous aurea trouvé chez le Jesuite et chez l'Advocat, qui peutetre ne surpasseront gueres les Srs van Durven, de qui je n'ay plus rien appris depuis la visite qu'ils m'ont rendu.
I shall be very glad to hear what you have found in the Jesuit and the Advocate, who may not surpass the Srs van Durven, of whom I have learned nothing since the visit they made to me.
No. 2343. Christiaan Huygens à Constantyn Huygens, frère. 19 juin 1684.
No. 2345. Christiaan Huygens à Constantyn Huygens, frère. 26 juin 1684.