The board is pleased to announce that.

But as we know, every advantage has its disadvantages. Ours are:

- The Science Centre is no longer available for various reasons.

- The alternative options are not available on Saturdays or only at high cost.

- The maximum number of audience members allowed to be fully 'coronaproof' in the halls is 30.

For now, GDT has decided, in consultation with Histechnica, to organise a lecture in the main hall of the KIVI building on Tuesday afternoon, 22 December, as a trial. You will soon receive an invitation to this.

You can then choose between being physically present in the hall or participating remotely via a video link. Also in the latter case, there will be an opportunity to ask questions. If more members prefer a place in the KIVI hall than there is room, a draw will be made.

The lecture will be given by Frank van den Berg, president of KIVI GDT, and the topic will be 'Lorenz, Lely, Thijsse and the afsluitdijk'. Below this post, there is already a short content of his lecture.

It is a first trial and we cannot guarantee that everything will go smoothly, we hope you understand this. If the trial succeeds, we can resume our regular activities in this way in January. All this, of course, with the proviso that there will be no tightening of corona measures.

Lecture: Lorentz, Lely, Thijsse and the Afsluitdijk on 22 December in the afternoon in the main hall of the KIVI building.

It took more than 40 years to realise the plans for the Afsluitdijk, namely from 1891 to 1932. Dr Ir Cornelis Lely was the inspiration, after many prior plans. There was much opposition to it. After the "minor" flood of 1916, progress was made through the work of a State Commission (1918 - 1926) led by Nobel laureate Prof Dr Hendrik Lorentz, then the scientific "curator" of the Teylers Foundation. His right-hand man in this was the Bloemendaler (later Prof Dr) Ir Jo Thijsse (son of biologist Dr Jac P. Thijsse). Lorentz and Thijsse developed a complex mathematical model of the current profiles in the Wadden Sea. As a result, the course of the Afsluitdijk was modified. Thijsse later became the founder of the Waterloopkundig Laboratorium in Delft. Frank van den Berg talks about all these plans and the extraordinary lives of the protagonists involved. He is not only chairman of the GDT department but also, among other things, a tour guide at Teylers Museum in Haarlem.