A graduate of the Naval Academy in the Class of 1923, Admiral Ageton has been a regular contributor to the Proceedings. He is particularly well known for his work in navigation, H.O. 211 (Dead Reckoning, Altitude and Azimuth Table) being simply referred to as “Ageton” by many a navigator the world round. He is also the author of The Naval Officer’s Guide, well known to reserve officers of World War II, the newly revised edition of which will contain the article here published.