By 1840s many astronomers had become convinced that there was at least one more planet besides the seven known till then. In 1846 the astronomer royal of England heard that the French astronomer Urbain Le Verrier was trying to determine the position of the new planet and hastily ordered a search for the heavenly body though he himself doubted its existence. The task was entrusted to Professor James Challis. One night Challis saw something that he thought might be the planet. He decided to check it out the following night. The next evening he was delayed by a visitor and when he got to the observatory the sky had clouded over and the weather remained bad for several days afterwards. In the meantime Verrier had mathematically worked out the position of the planet. He wrote to the Director of the Berlin Observatory, Johann Encke and informed him about his findings. The letter reached Encke on his birthday but the director did not consider it a great present. He, like the astronomer royal of England did not believe it was worthwhile searching for an eighth planet. He passed on the letter to his assistant Johann Galle and left for his birthday party. The young assistant, who had obtained his doctorate just a year earlier, did not have to search very hard for the planet. It was where Verrier had said it would be. But the evening's work made Johann Gottfried Galle famous. He went down in history as the first man to see the planet we now know as Neptune.