His Majesty the King Rama IV also known as King Mongkut used his spare time to study Astronomy. He was able to predict the occurrence of the total solar eclipse at Wa Kor sub-district on August 18 1868. In 1982, the Bangkok Celebration Anniversary Year, the Thai Government named him the ‘Father of Science of Thailand’ The Thai scientists are grateful for his spirit in introducing modern science to national development. Therefore, they all reached a conclusion to make August 18th of every year the ‘Thai National Science Day'.