Reed water tube boiler straight tubes through which water and steam circulated more freely, it was considered by some contemporary writers on the subject such as Leslie S. Robertson as "behind" in its circulation because of the absence of down-comers. Whereas the Yarrow boilers fitted to the armoured cruiser of 1905 evaporated 11.664 pounds (5.291 kg) of water per pound (454 g) of coal at 100 degrees centigrade (212 degrees Fahrenheit) with natural draught, by the same measure a Reed boiler as fitted to the torpedo boat destroyer of 1896 evaporated 12 pounds (5.44 kg). An advantage of the Yarrow boiler was in weight:
Past sea level no longer positive, and shown to be quite large. At times during Earth's long history, the configuration of the continents and sea floor has changed due to plate tectonics. This affects global sea level by altering the depths of various ocean basins and also by altering glacier distribution with resulting changes in glacial-interglacial cycles. Changes in glacial-interglacial cycles are at least partially affected by changes in glacier distributions across the a Earth. The depth of the ocean basins is a function of the age of oceanic lithosphere (the tectonic plates beneath the floors of the world's oceans). As older plates