388 Proceedings of the Royal Society of Edinburgh. [Sess. 
departments of meteorology and oceanography, to which, in my opinion, 
less than justice was done by his contemporaries. His first publication 
was in the Proceedings of the Royal Society of Edinburgh for 1885, on 
observations which he made when working with me at Granton on the 
measurement of air temperature by means of Dr John Aitken’s experi- 
mental thermometer screens. Soon afterwards, he discussed the hygrometry 
of Ben Nevis, and published an interesting collection of the weather folk- 
lore of Scottish fishermen, picked up while working for the Fishery Board. 
In 1901 he read to the British Association meeting at Glasgow a suggestive 
paper on the possible cause of glacial and interglacial periods by a com- 
paratively slight fall in atmospheric temperature at the poles with no 
change in the equatorial belt. He showed how the quickening of the 
planetary atmospheric circulation and the resultant acceleration of oceanic 
currents might well account for most of the facts. 
His two little books on meteorology have an importance quite out of 
proportion to their size. In his Elementary Meteorology , published as a 
University Extension Manual in 1893, he gave for the first time a system 
of meteorology in which the physical facts of wind motion were made the 
basis of the weather map, the arrangement of the isobars being introduced 
as the result of the winds, rather than as their cause. This little book 
did much to vivify interest in meteorology. His Climate and Weather, 
published in 1912, showed equal freshness and originality of view-point, 
and illustrates the importance, in treating climatology, of a wide and deep 
knowledge of other departments of physiography. 
Dickson’s chief contributions to science were the results of his oceano- 
graphical researches, chief amongst them that carried out at Oxford in 
conjunction with the Marine Department of the Meteorological Office. For 
several years he obtained regularly samples of surface water, collected by 
Atlantic liners at numerous points on their voyages between Europe and 
America, and a much more extensive series of temperature observations 
made as part of the ship’s routine. He analysed the samples, and constructed 
an elaborate set of maps of salinity and temperature from which he deduced 
the movements of the surface waters for each month in a consecutive 
period of two years, January 1896 to December 1897. The accuracy of 
the work was of a higher order than had previously been found possible, 
and the duration was greater than that of any previous attempt to keep 
continuous track of seasonal changes. The result was to show that the 
seasonal variations in the surface water were due partly to changes in 
situ and partly to the translational swing of currents at various seasons 
to the right or left of their normal lines of flow. 
