The events of this story took place in Poland before the establishment of the great universities. In those times, various aristocrats supported private schools of science called academies.
In the province of Lithuania there were three such academies, each supported by different princes. One, located near Vilna, was owned by Prince Radziwill, another, near Vitebsk, was owned by Prince Sheksinski, and the third, located on the shores of the Dnieper, between Dobrovna and Liadi, was owned by Prince Decrit. In those days, the Polish people were not very accomplished in the sciences, and the actual instructors at these academies were imported from France.
On the property of Prince Sheksinski there was a big palace, and in its courtyard was a sundial. For two years the sundial had not functioned properly, and would not tell the correct time between the hours of two and five in the afternoon. The prince had already consulted many leading experts, scientists, and professors about this problem, but no one could figure it out. When the prince learned that there was a very wise Jew who was well known for his problem-solving, he sent for the Alter Rebbe (Rabbi Shneur Zalman of Liadi, founder of Chabad Chasidut) to come to his property and help him discover the cause of the sundial's malfunction.
At first, the Alter Rebbe refused to go, heeding the advice of our Sages not to get involved in political matters, but after he was reassured that no precious time devoted to Torah learning would be wasted, he agreed, and traveled to the palace.
Even though the Alter Rebbe spoke Polish well, he preferred to speak Yiddish, and, so, his father-in-law served as translator. After examining the sundial several times during the problematic hours, he said, "It is brought down in the Talmud that the sun is directly overhead in the middle of the day, and that nothing can intercede between the sun and the earth during this time except for clouds. However, after noon, when the sun starts to go down, it is possible for various objects to interfere with the sun's rays. It is my opinion that there is a mountain to the south of us, at a distance of 12 to 15 parsaot. It seems as if the trees growing on its peak have grown too tall and are obstructing the sun's rays between the hours of 2 and 5, preventing them from reaching the sundial. When the sun sinks little further, the trees are no longer in the way, and the sundial works properly after this time."
The prince was amazed at the Alter Rebbe's reasoning, and sent a special emissary to find the area described to see if indeed it was so.
Upon hearing this, the head of the prince's academy, a leading engineer by the name of Professor Marseilles, ridiculed the opinion of the Alter Rebbe. He laughingly said, "Those Jews imagine that all wisdom is contained in their Talmud. Zelig the doctor learns his medicine from it, Boruch the gardener learns how to prepare the soil for planting, and Zanvil the merchant learns how to cheat the landowners from this Talmud... Now, this character imagines that the sun's rays only reach the earth according to the Talmud!"
The Alter Rebbe replied to his criticism, saying: "Empirical evidence is the axe which fells those who are arrogant in their belief in science."
"Is that also a saying found in your Talmud?" asked the professor.
"No," answered the Alter Rebbe, "it is attributed to the great Galinus, who also had to suffer with those who were arrogant."
Word leaked out about the Alter Rebbe's diagnosis of the problem, and before the prince could find the exact spot, a group of troublemakers found the trees which were obstructing the light and chopped them down without telling anyone.
A few days later, when the grounds-keeper on the prince's estate reported that the sundial was in perfect working order, the prince was very surprised, but it was simply thought that the clock had spontaneously fixed itself.
Eventually, the Alter Rebbe's father-in-law heard the rumor that the trees had been chopped down in secret, and he found those responsible and brought them before the prince, demanding that they tell him what they had done. Admitting their guilt, the truth of the Alter Rebbe's wisdom was confirmed, and his fame soon spread among the ranks of the scientific community in Poland.
