A major link exchange dealing with

William FellerThe most authoritative source of biographies of outstanding mathematicians offered by the WWW is The Mac Tutor History of Mathematics Archive, Scotland, UK. It has been designed and prepared by professors John J O'Connor and Edmund F Robertson. This enormous web site contains biographies of three Croatian mathematicians:

It is my pleasant duty to report that since the May 2007 the article dealing with William Feller has a link to the following web site

www.croatianhistory.net/etf/feller.htmlwhich is, without any doubt, the most exhaustive presentation of Feller's spectacular scientific biography. By now this web page has more than 60 printed pages, including numerous photos.

I take the opportunity to express my deep gratitude to professor John J. O'Connor for a very fast response to my e-mail, in which I proposed a few corrections regarding Feller's biographical data in the first three sentences.

Since similar mistakes can be found throughout the web (the source of mistakes is Gian Carlo Rota, a well known Italian-American mathematician), I find it pertinent to include a part of my recent e-mail sent to professor O'Connor, in order to indicate the problem:

... I have found the MacTutor History of Mathematics web pages very useful, my sincere congratulations for a truly great job. To introduce myself, I am employed at the University of Zagreb, Croatia, working in elliptic PDEs and fractal analysis of Dynamical systems. Since the last year I began to collect data about William Feller in a systematic way.
I have recently been encouraged by Professor John Aldrich (Division of Economics, School of Social Sciences, University of Southampton) to write to You. He has created a very nice web page "Figures From the History of Probability and Statistics", available at
http://www.economics.soton.ac.uk/staff/aldrich/Figures.htm
Last year I have been asked also by descendants of Feller's father, living in Zagreb, to contact You. Namely, some of the data about Feller provided by Gian Carlo Rota, and cited at the beginning of Your (otherwise excellent) article, are incorrect. In particular, Feller's second name, contrary to Rota's claim, was always Feller. Also the name of "Willibrord" provided by Rota is wrong, as well as his claim about a "Slavic tongue twister" (Rota must have misunderstood something).
It is unfortunate that these (Rota's) mistakes appear in the first three sentences of Your article. Alow me to cite these three sentences from the very beginning of Your article, with my remarks in angular brackets:
**William Feller**'s parents were Ida Perc [maybe rather Oemichen - since this was her father's second name; Perc or Pertz is the second name of her mother] and Eugene [should be Eugen] V Feller - well that is not strictly true since the family surname was not Feller [this is wrong] but, as Gian-Carlo Rota put it, a Slavic tongue twister [!?] which William changed when he was about twenty years old [he changed Vilim to Willy in Germany, but he was born as Vilibald Srecko, and changed to Vilim at the age of 17, when entering the University of Zagreb], so his father never used the name Feller [totally wrong claim of Rota].
In fact his first name was not William [true: he was born as Vilibald Srecko in 1906] either! Rather it was Willibrord [no, it was Vilibald Srecko (Srecko=Felix)] which was the name of the Saint [Vilibald] whose day falls on his birthday.
His mother was a Roman Catholic and so he was christened Willibrord [Vilibald], but was known as Willy (and he even [understandably for the period of his life in Germany] used the name Willy Feller on his papers into the 1940s). ...
**Article by:** *J J O'Connor* and *E F Robertson*
A. Following a recent suggestion of Professor Aldrich, I am free to ask You to take into account my web page containing a detailed Feller's biography (more than 60 pp), available at the following address:
www.croatianhistory.net/etf/feller.html
hoping that in the future it might appear among links offered at the end of Your article about Feller. I understand that it will take time until You check the quality and reliability of my article.
... |

As it usually happens in mathematicis and with mathematicians, there were more fruits than expected! Indeed, professor O'Connor kindly sent me a PDF file containing Feller's plenary lecture delivered at the 1958 International Congress of Mathematicians in Edinburgh (Scotland).

Expressing again my deep appreciation to professors John J O'Connor and Edmund F Robertson for their wonderful web site, I invite You to visit and enjoy The Mac Tutor History of Mathematics Archive.

Many thanks also to Nenad Bach for encouriging me to write this article.

PS. For those who maybe doubt that William Feller is an important figure in the History of Mathematics, I provide an amazing list of mathematical notions bearing his name:

- Feller theory
- Feller process
- Feller minimal process
- strong Feller process
- doubly Feller process
- Feller property
- strong Feller's property
- weak Feller's property
- Feller class
- Feller chain
- Feller-McKean chain
- Feller-Markov chains
- Quasi-Feller Markov chains
- Feller extension
- Feller's decomposition
- Feller's road map
- Feller diffusion process
- two-parameter Feller process
- Doubly-Feller process
- Feller branching diffusion
- Feller transition function
- Feller's representation
- Feller's construction
- Feller transition probabilities
- Feller-Reuter-Riley (FRR) property
- Feller-Reuter-Riley transition function
- Feller continuity
- Feller semigroup
- Feller-Dynkin semigroup
- Feller-Dynkin diffusion
- Feller-Dynkin process
- Feller-Dynkin propagators
- Feller-Dynkin characterizations
- Feller generator
- Feller's transformation
- Feller's randomization technique
- Chung-Feller theorem
- Feller-Lindvall diffusion
- Feller-Lamperti-Lindvall invariance principle
- Feller-Pareto distribution
- Feller data
- Feller's parametric equations
- Feller operator
- sub-Feller operator
- discrete Feller operator
- selfadjoint Feller operators
- Feller kernel
- Feller stochastic kernel
- quasi-Feller kernels
- Feller approximation
- Feller perturbation
- Feller resolvent
- Feller minimal resolvent
- Feller boundary
- Feller's natural boundaries
- Feller classification
- Feller boundary classification
- Feller-Wentzell-type boundary conditions
- Feller-Ventcel' end conditions
- Feller-Ueno boundary decomposition
- Feller's domainated variation
- Feller alternatives
- Dirichlet-Feller operator
- Trotter-Feller operator
- Feller potential
- Riesz-Feller potential
- Riesz Feller derivative
- Kato-Feller (Feller-Kato) potential
- Kato-Feller class
- Kato-Feller norm
- Kato-Feller property
- Trotter-Feller operator
- Keldysh-Feller operator
- Keldysh-Feller conditions
- Feller Brownian motions
- co-Feller operator
- co-Feller Markov chain
- stochastic compactness in Feller's sense
- Feller's test for explosions
- Lindeberg-Feller condition
- generalized Feller condition
- Feller-Lindeberg central limit theorem
- Bernstein-Feller central limit theorem
- Feller-Khintchine-Lévy central limit theorem
- Feller's renewal theorem
- Blackwell-Feller-Orey renewal theorem
- Feller's theory of recurrent events
- Feller's recurrent events
- Feller's discrete time recurrent phenomena
- concept of Feller-Gantos
- Feller-Jirina-Lamperti convergence
- Erdös-Feller-Pollard theorem
- Feller's paradox
- Chernoff-Feller-Klotz-Stone-Sievers approach
- Aleksandrov-Busemann-Feller theorem
- Busemann-Feller-Aleksandrov theorem
- Busemann-Feller (BF) basis
- Feller measures
- Feller invariant measure
- Feller system
- Feller-Arley process (model)
- Feller-Arley birth and death process
- Feller minimal birth-death process
- Feller minimal solutions
- Feller's solution
- Non-Feller model
- Quasi-Feller model
- Feller's coupling method
- Dickey-Feller test
- Lévy-Feller process
- Lévy-Feller diffusion
- Lévy-Feller advection-dispersion process
- Markov-Feller (Feller-Markov) process
- Markov-Feller semigroup
- Markov-Feller (Feller-Markov) operators
- Markov-Feller pair
- Feller semi-Markov control processes
- Krein-Feller operators
- indefinite Krein-Feller differential operators
- Krein-Feller (eigenvalue) problem
- Krein-Feller second order derivative
- Feller-Miyadera-Phillips theorem
- Hille-Phillips-Feller-Miyadera conditions
- Hille-Yosida-Feller-Phillips-Miyadera semigroup
- Hille-Yosida-Feller theorem
- Feller cocycle
- Feller-Jirina theorem
- Feller-Jirina scheme
- Feller-Tornier constant
- Generalized Feller equation
- Feller solutions to SPDE's
- Feller's law of the iterated logarithm
- Feller-Erdös-Kolmogorov-Petrovski criterion
- Petrovskii-Erdös-Feller integral functional
- Feller-Fokker-Planck equation
- Fokker-Planck-Kolmogorov-Feller equation
- Kolmogorov-Feller test
- Kolmogorov-Erdös-Feller integral tests
- KolmogorovFeller weak law of large numbers
- Kolmogorov-Feller (Feller-Kolmogorov) equation
- Kolmogorov-Feller integro-differential equation
- Kolmogorov-Feller-Stratonovich equation
- Kolmogorov-Feller theory of Markov processes
- Kolmogorov-Feller jump processes
- Kolmogorov-Feller-type operator

The list has been obtained using references on MathSciNet in the period between 1970 (since Feller's death) and 2007, citing Feller's name.

Paul C. Kettler, Norway:

*...the personal aspects of creative lives are just as important I believe as the professional aspects. At the lowest level, it is personal interaction, after all, which produces great collaborations. Feller and Kolmogorov, across continents and ideologies, is the perfect example.*

Since the May 2007 my web page about William Feller has been translated into Croatian by two students of mine, Ms Marta Kolar and Ms Ines Leskovar (University of Zagreb, Faculty of Electrical Engineering and Computing):

www.croatianhistory.net/etf/fellerh.htmlFormated for CROWN by prof.dr. Darko ®ubriniæDistributed by www.Croatia.org . This message is intended for Croatian Associations/Institutions and their Friends in Croatia and in the World. The opinions/articles expressed on this list do not reflect personal opinions of the moderator. If the reader of this message is not the intended recipient, please delete or destroy all copies of this communication and please, let us know!