The empire on which the sun never sets in all the Asian Subcontinents, and islands in the Atlantic, Indian and Pacific oceans. However, it was under his son Philip III of Spain that the Spanish Empire acquired its largest extension. Philip III and his son Philip IV of Spain were also kings of Portugal among other territories besides Spain, which made both of them the rulers of the greatest extension on earth of all time, simply by joining the global territories of Spain and Portugal empires account for more extension than any other king has ever ruled. In 1585, Giovanni Battista Guarini wrote "Il pastor fido" to mark
Mid-ocean ridge in past calcite seas, meaning that the Mg/Ca ratio in an organism's skeleton varies with the Mg/Ca ratio of the seawater in which it was grown. The mineralogy of reef-building and sediment-producing organisms is thus regulated by chemical reactions occurring along the mid-ocean ridge, the rate of which is controlled by sea-floor spreading. Mid-ocean ridges are generally submerged deep in the ocean. It was not until the 1950s, when the ocean floor was surveyed in detail, that their full extent became known. The "Vema", a ship of the Lamont-Doherty Earth Observatory of Columbia University, traversed the Atlantic Ocean, recording data