Some biographies of Farwerck mention that he travelled for work. My first thought was that he combined business with pleasure and took the opportunity to travel to places to take photos for his books. This proved to be not true. All photos that he used in books and lists as having been made himself, are taken in the Netherlands. He does use photos of other countries but these are either taken from other works or sent to him by correspondents. So or did he not travel as much as suggested?
Biographies also mention that Farwerck studied in the UK and in Germany so apparently he has been travelling since early in his life. It is hard to follow his travels, but there are two sources in which we can follow them a bit: Freemasonry and the Rotary.
In 1921/2 Farwerck appears to have been present at an Esperanto congress in Frankfurt, Germany. From the Netherlands to Frankfurt is ‘doable’. Besides, he even had family in Germany from his fathers side. In the same year, he also appears to have been in Prague to help to found another Esperanto lodge there. That is already quite a trip. He receives the 33º in Freemasonry so that he can represent the foreign lodges that fall under the Dutch jurisdiction at the international council in Paris. (I haven’t been able to find out if he actually ever was in Paris for that purpose.)
Later in 1922 a lodge was to be founded in Wien/Vienna, but due to reasons of health, Farwerck had to send a representative. Apparently he wasn’t always fit enough to travel. In 1923 or 1924 he seems to have visited the lodge in Prague again though and again in 1927.
In 1928 the Rotary Club was founded in Farwerck’s home town and in the same year he mentions having visited Rotary Clubs in Copenhagen (Denmark) and Göteborg (Sweden).
In 1930 he again travels for his Masonic organisation and makes a long tour alongside lodges in Hamburg, Berlin, Prague, Wien and Frankfurt. That’s quite a tour.
At his Rotary Club in the year 1931 he mentions having been in Stockton, UK.
Also for the N.S.B. he travelled. In 1937 he visited the Externsteine and the Hermannsdenkmal in the vicinity of Detmold, Germany.
Not a very detailed few of Farwerck’s travelling. We can see that he travelled as far North as Göteborg to as far South as Wien and from Stockton in the West to Berlin in the East. He can’t have made all travels by car alone, since the Øresund Bridge between Copenhagen and Malmö was only opened in the year 2000. For his Sweden trip, he must have used a boat or a plane.
Would he have made other trips not mentioned in the sources that I have found? Probably. He most likely had the means to travel. I suppose he’d drive to Germany every so often at least. Hard to say until I run into new information.