Hydrographical Observations from Danish Light-Vessels

Abstract

THE recently published “Mean Values of Observations from Danish Light-Vessels” is a pamphlet issued as a special reprint from the Nautical Meteorological Annual, 1932, of the Danish Meteorological Institute. There are numerous tables summarising observations made at Danish light-vessels, such as the salinity at 8 a.m. of the sea-water at the surface and at various depths down to the ocean bottom, frequencies of horizontal visibility of the atmosphere between certain limits in miles, and frequency of ocean currents of various velocities, at different depths of the ocean. These are all long-period averages, mostly referring to 1901-30 or 1903-30, but for sea surface temperature going back to 1881, and for visibility beginning only in 1918, when the modern system of measuring visibility was introduced, and extending only to 1927. This is clearly not a work for the ordinary student of meteorological literature, but one for the specialist in hydrographic work and for the sailor, and even to those it must be mainly a work of reference. The number of individual observations on which it is based is very large, and the statistical value of the averages is proportionately great.