Publication of Astronomical Observatory of Belgrade, Vol. 105, 2024, Page 37, https://doi.org/10.69646/14sbac33a
BOOK OF ABSTRACTS: XIV Serbian-Bulgarian Astronomical Conference, 23 - 27 September, 2024, Vrnjačka Banja, Serbia. Editors: Milan S. Dimitrijević, Evgeni Semkov, Zoran Simić, Goran Damljanović, Momchil Dechev

While working on the correspondence of Milutin Milanković (Dalj, 1879-Belgrade, 1958) at the Serbian Academy of Sciences and Arts (SANU) in Belgrade, I came across a letter sent by Milanković to the Royal Hungarian Academy of Sciences in Budapest. In it, Milanković thanks the Academy for allowing him to spend his years of internment during the First World War in its library and enabling him to engage in scientific work. In those years, the text of his book "Mathematical theory of thermal phenomena caused by solar radiation" was written, and as a sign of gratitude he sent them its original typescript, which he wrote at the time under the title "Matematische Grundlagen der kosmischen Strahlungslehre". The letter is dated April 2, 1941. Given that Belgrade was bombed just a few days later, on April 6, 1941, I was interested in whether the manuscript reached the Hungarian Academy. To my inquiry, they replied that they had received it and that it was in the archive.The path of the manuscript did not go as Milutin Milanković planned. After the First World War, it was desirable that the book be printed in French. Given that Milanković did not speak French well enough, the translation from German to French was entrusted to Ivan Djaja (Le Havre, 1884 - Belgrade, 1957) and Mihailo Petrović Alas (Belgrade, 1868 - Belgrade, 1943). Milanković duly copied his original manuscript in German and handed it over to Djaja and Petrović. After completing their translation, Milanković also copied the translation. Both manuscripts are in SASA. The book was published in Paris in 1920 under the title "Théoriemathematique des phénomènes thermiques produits par la radiation solaire". The results published in this book have attracted the attention of many scientists. Vladimir Köppen and Alfred Wegener invited Milutin Milanković to collaborate in their book "The climates of the geological past".On April 20, 2017, in the Library and Information Centre of the Hungarian Academy of Sciences a memorial plaque in memory of Milutin Milanković was unveiled.