Gerrit van der Mey

Gerrit van der Mey

Gerrit van der Mey at a Braille phone.

Gerrit van der Mey (5 January 1914 - November 2002) was the son of a bulb grower in Lisse, the Netherlands. At the age of 4 he got meningitis due to an open connection in his ear, causing him to become completely blind. He got his primary school education at a special school for the blind in the Netherlands. He then got his high school education in Marburg, Germany, also a special school for the blind. His teacher, Friedrich Mittelsten Scheid, discovered Van der Mey had a great talent for mathematics. In 1941 Van der Mey went to Leiden to study mathematics, but he left and went to the "Vrije Universiteit" in 1943, because of the upcoming war. He graduated here Cum Laude with Koksma and Haantjes.

Van der Mey at a Braille Typewriter

Gerrit van der Mey, his wife Suzanne Melgerd and friend Willem van der Poel. Communication was possible thanks to an electronic Braille typewriter.

Communication

At that time the open connection in his ear could not be permanently healed and in 1945 he got meningitis again. This time he lost his hearing and his sense of balance. It took a long time before he was able to walk again with a guide dog and using the feeling in his feet for balance. At Marburg he had learned the Lorm alphabet which uses strokes and taps on the fingers to communicate. For close friends and family this was a good way to be able to communicate with him without the need for machines. A tool that was used by him a lot was the Braille box, which has buttons for six pins that can be used to form Braille letters.

While learning to walk again he also continued with his study of mathematics and he obtained his doctoral degree in 1946 for a thesis with a geometrical background, which is remarkable for a blind person. In early 1951 he started working for the PTT Lab to program the new computers. A big advantage for Gerrit was that programming was a new profession so there was little literature he had to study before starting.

Henk Mol created the first electronic Braille typewriter in that same year. There was a keyboard on one end where people could type a letter that could be sensed in Braille on the other end. Although feeling Braille on one spot required some practice, this typewriter enabled Gerrit to be able speak to everyone again. Since Gerrit could still speak well, he always spoke what he felt from the Braille.

Oval Office

When Gerrit traveled to America during a two week storm it was nearly impossible for him to walk on the rocking ship, because he lacked a sense of balance. On the other hand he couldn't get seasick either.

In 1957 he went on a tour through the United States and Canada with the Helen Keller foundation, a foundation supporting the deaf-blind, accompanied by his wife Suzanne Melgerd and Willem van der Poel. They traveled with other deaf-blind people and gave lectures. One of the highlights of the trip was a visit to president Eisenhower in the Oval Office.

When Willem van der Poel becomes a professor at the Technische Hogeschool Delft Gerrit goes with him. He works there until 1978, when he retires and lets go of Computer Science entirely.

In 1982 he is nominated "Ridder in de orde van Oranje Nassau" (Knight in the Order of Oranje Nassau), a high decoration in the Netherlands granted by the queen. When in 1983 his wife Suzanne passed away, Gerrit went through a rough time. His positive attitude towards life remained and he remarried a woman that had helped him after Suzanne died. They divorced again a year later. Gerrit reacted "oh well, I have learned a lot from this". His last years were spent at a center for deaf-blind people in Beek where he passed away in November 2002.

Van der Mey in the Oval Office

Gerrit van der Mey in the Oval Office, visiting president Eisenhower together with Willem van der Poel.

Gerrit's work

As said above he worked at the PTT Lab from 1951. Here he started working with Willem van der Poel who became a lifelong friend and colleague. He only did a few projects there. First he wrote programs for the PTERA. Programs for the use of floating point calculations were amongst them. His work was used by the PTT Lab for calculations on cables, filters on multiple wave carriers, celestial mechanics and other areas.

For the ZEBRA he created an assembler, operating system, floating point service and Simple Code. Simple Code is an easy code that can be used to program problems. A simulator for Simple Code was later also created for the X1.

The ALGOL-68 report was written in 5 different fonts, while Gerrit only had 63 Braille characters to work with.

Gerrit was very interested in LISP, and he created various implementations of it. Because LISP had a very small syntax and its semantics was defined in LISP this was right up his alley. He created LISP implementations for ZEBRA, PDP8 and PDP9. He also created several implementations for later versions of LISP, like LISP 1.5 and halfword LISP. ALGOL-60 was another language that Gerrit worked with. Together with P.A. Witmans and G.M.M. Mulders he wrote an ALGOL-60 compiler for the ZEBRA. He also made implementations for C and ALGOL-68 with the aid of several students.

Apart from making implementations he also did a lot of theoretical work. He wrote an article on combinators in LISP and helped give a lot of insight in the recursion operator or "paradoxic combinator" as he called it. He also worked his way through the ALGOL-68 report and made some suggestions to WG 2.1, the IFIP working group that designed ALGOL 68.

Working with Gerrit

Because of his disabilities to see and hear, Gerrit worked a little different compared to other people. Willem van der Poel noted that when he and Gerrit were testing software, Gerrit would often be able to name which specific line of code the error occurred at. He seemed to have a nearly photographic memory for code.

For many projects Gerrit would write a program, then others would run tests and when errors were found or extra features needed to be added they would suggest solutions and implement them. Because Gerrit often worked at home these debug sessions would take a lot of long distance communication. Luckily Braille phones and telexes were available at the time. Using these devices, Gerrit could feel Braille letters and type and the other end could just type the letters.

When something went wrong in the assembler, Van der Mey would say something like "Oh, you should take a look at instruction 358, that's probably where the error is."

Willem van der Poel[1].

Van der Mey could still do many things on his own. He typed most of his reports himself, his wife would then correct any language mistakes, but he was very precise so usually there weren't that many. Before he lost his hearing Gerrit played the piano. Surprisingly he still could after losing his hearing, despite not being able to hear himself play anymore.

Gerrit also liked to travel. He could go from his home to Willem van der Poel by himself, if the train personnel was informed beforehand. He also traveled outside the Netherlands to Mainz and München (Germany), for instance to give lectures. This was possible because he could still speak very well. He always thought that was because of some sort of primal hearing enabling him to still "hear" himself talk. After his retirement he worked on his ideas about this primal hearing with professor Ritma who specialized in the human ear.


References

  1. Poel, W. van der , "Met Drieënzestig Symbolen", Nieuw Archief voor Wiskunde, vol. 6, issue 4: Koninklijk Wiskundig Genootschap, pp. 312-316, 12/2005.
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