Time at Sea and the Astro-Nomical Day

Abstract

IN spite of the stress of war, the British, French, and Italian Admiralties found opportunity last year to come to an important decision on the question of timekeeping at sea. Hitherto the general practice appears to have been to set the ship's clocks to the local time corresponding with the place where observations were made, ancl continue its use until further observations were secured. In consequence, two vessels speaking each other might record different times for their meeting; cases are not unknown where it has been of legal importance to ascertain the exact time of a death occurring at sea, which was a matter of some difficulty on the old system. It has now been resolved to extend to the sea the system which has been so widely adopted on land, of keeping time which differs by an integral number of hours from Greenwich time, the hour being changed on crossing meridians 150 apart. In this connection it may be noted that there is need of a short name for the regions that keep, the same time. The word “zone” is to be deprecated, since both by root-meaning and by usage it suggests a belt parallel to the equator. The word “lune” has been adopted in works on spherical trigonometry, but is apt to suggest a connection with the moon. The French use the somewhat cumbersome term “fuseau horaire.” Mr. T. C. Hudson suggests the term “douve”; it means a barrel-tave, which has some resemblance to the shape of the regions in question.