In 1864, Charles Piazzi Smyth, Astronomer Royal for Scotland, gave in his book Our Inheritance in the Great Pyramid the coordinates with 30°00′N 31°00′E﻿ / ﻿30.000°N 31.000°E﻿ / 30.000; 31.000﻿ (Geographical centre of all land surfaces on Earth (Smyth 1864)), the location of the Great Pyramid of Giza in Egypt.[2][3] He stated that this had been calculated by "carefully summing up all the dry land habitable by man all the wide world over".[2]