At the time it was built the Washington Monument was the tallest building in the world. It was the tallest structure in the world between 1884 and 1889, after which it was overtaken by the Eiffel Tower in Paris. It is still the tallest freestanding masonry building in the world. It is still the tallest monumental column in the world if all are measured above their pedestrian entrances. The aluminum apex, composed of a metal that at the time was the rarest metal in the world, was cast by William Frishmuth of Philadelphia. At the time of casting, it was the largest piece of aluminum in the world. Before the installation, it was put on public display at Tiffany's in New York City and stepped over by visitors who could say they had "stepped over the top of the Washington Monument". It was 8.9 inches (23 cm) tall before 3⁄8 inch (1 cm) was vaporized from its tip by lightning strikes during 1885?1934, when it was protected from further damage by tall lightning rods surrounding it. Its base is 5.6 inches (14 cm) square. The angle between opposite sides at its tip is 34?48'. It weighed 100 ounces (2.83 kg) before lightning strikes removed a small amount of aluminum from its tip and sides.[30] Spectral analysis in 1934 showed that it was composed of 97.87% aluminum with the rest impurities.