Karel (Charles,Carl) Roberti (date and place birth unknown- date and place of death unknown)-presumed dutch nationality
Karel Roberti conducted his first rocket experiment on the shores of Katwijk-aan-Zee on the 6 th of december 1934. His rocket called Meteor exploded on ignition. Several attempts followed but they weren't very succesfull : the distances covered by his rockets were minimal. His rockets were just sky-rockets ,purchased from the well known fireworks producers,A J Kat in Leiden. Most of the experiments were held at remote areas with very little publicity and eye-witnesses.
His association with the N R B (abbreviation of Nederlandsche Raketten Bouw- translated as Dutch Rocket Construction Inc) with chairman stampdealer Gerard Thoolen did arouse suspicion that personal benefit by selling rocket covers to stampcollectors was more important then the scientific aspect of his experiments. The rocket covers with the colorful cachets were advertised worldwide by Thoolen and were sold at high prices.
In 1935 numerous articles on what was called the "Rocket Post Swindle"appeared in the leading Dutch stampmagazine "Maandblad voor de Philatelie" . It was their conclusion that Roberti and Thoolen were nothing more then con merchants and had no scientific background.That's probably the reason why the N R B performed their next experiments abroad.
On the 9th of May 1935 he conducted the first Belgian rocket mail experiment on the beach of Heyst-aan-Zee - Duinbergen in collaboration with the Belgian Postadministration. Two more Belgian experiments followed on the 04 th of september and the 04 th of June 1936 at the same place.
Roberti also had flights in Luxembourg (Clervaux 17th of July 1936) and on the 13th of september 1936 he wanted to send rockets across the Channel from Calais to Dover but was thwarted by French officialdom.
At the end of the thirties, I've lost track of Roberti and his experiments.
First Test : 09/05/1935 :Heyst - Duinbergen (2 covers)
Second Test : 04/09/1935 : Heyst - Duinbergen (2 covers)
Third Test : 04/06/1936 : Knocke Albert Plage (2 covers)