The Sailing Flight of the Albatross

IN NATURE, vol. xxxix. p. 230, the late Mr. William Froude, in a letter to Sir William Thomson, on the subject of the “Soaring of Birds,” gives a short account of the well-known and often discussed sailing flight of the albatross; and says that after long consideration the only explanation, which presented itself to his mind was, that the birds use the upward current caused by the lifting of the air from the bottom of the trough to the level of the crest of an advancing wave. Mr. Froude by a rough calculation—the waves being supposed 10 feet from hollow to crest—concludes that an upward current of 3 feet per second may be caused in this manner, and states that the bird's movements were often in accordance with this explanation, though it was often impossible to affirm or deny the accordance.