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:
Sea level particular location. Sea levels can be affected by many factors and are known to have varied greatly over geological time scales. The careful measurement of variations in MSL can offer insights into ongoing climate change, and sea level rise has been widely quoted as evidence of ongoing global warming. The term "above sea level" generally refers to above mean sea level (AMSL). Precise determination of a "mean sea level" is difficult to achieve because of the many factors that affect sea level. Instantaneous sea level varies quite a lot on several scales of time and space. This is because the