On the Eiffel Tower, 72 names of French scientists, engineers, and mathematicians are engraved in recognition of their contributions. Gustave Eiffel chose this "invocation of science" because of his concern over the protests against the tower, and chose names of those who had distinguished themselves since 1789. The engravings are found on the sides of the tower under the first balcony, in letters about 60 cm (24 in) tall, and were originally painted in gold. The engraving was painted over at the beginning of the 20th century and restored in 1986–87 by Société Nouvelle d'exploitation de la Tour Eiffel, the company that the city of Paris contracts to operate the Tower. The repainting of 2010–11 restored the letters to their original gold colour. There are also names of the engineers who helped build the Tower and design its architecture on a plaque on the top of the Tower, where a laboratory was built as well. Source: Wikipedia (en)