458 LIFE OF HORACE BENEDICT DE SAUSSURE 



of meteorology as with the application of meteorological methods 

 to the measurement of heights and to the explanation of the 

 differences between atmospheric phenomena at different altitudes. 

 So far as I have been able to ascertain he never proposed a system 

 of national observations, nor attempted to map any of the elements 

 of climate, an advance which was reserved for Humboldt in the 

 next generation. Like Franklin, he was inclined to attribute 

 more importance to electricity than to heat in controlling meteoro- 

 logical phenomena, though he did recognise the vital relation of 

 heat to evaporation and condensation of water vapour as fully as 

 was possible before the foundations of thermodynamics had been 

 laid. 



The most striking characteristics of de Saussure as a meteoro- 

 logical observer were his extraordinary skill in manipulating 

 delicate instruments in almost impossible conditions and his 

 accuracy in reading and recording. He differed from the majority 

 of his contemporaries also in not making observations for their 

 own sake. He always had some definite problem in mind, and 

 the ingenuity with which he planned and executed his experiments 

 was matched by the lucidity of his reasoning on the results. He 

 had the mind of a true experimental philosopher, being singularly 

 free from prepossessions and apparently quite without prejudices. 

 He had the advantage of living at a period when no standards of 

 scientific orthodoxy had been set up, and there were no recognised 

 authorities whose views, in so far as they were erroneous, an 

 investigator had to contend against. As yet such authorities 

 had not arisen, and the field was free from all obstructions. 



Chemists had already demonstrated the fact that atmospheric 

 air consisted of a mixture of oxygen and nitrogen with a small 

 proportion of carbonic acid, but the proportion of oxygen or vital 

 air was believed to vary considerably from place to place, hence 

 it was assumed that the healthiness of a district depended on a 

 larger proportion of oxygen being present in the air, and the use 

 of the eudiometer for measuring this proportion was popular with 

 scientific travellers. The methods of determination were crude 

 and the results obtained are now known to be fallacious. How- 

 ever, de Saussure and his son believed that they found indications 

 of a reduced proportion of oxygen at high mountain stations, and 

 this is in accordance with modern theory. The facts, however, 

 lie outside meteorology. 



The finest piece of pure meteorological observation which de 

 Saussure carried out was on the Col du Geant at an altitude of 

 1 1 ,030 feet above sea-level from the 5th to the 1 8th July 1788. This 

 may indeed be looked on as the first establishment of a mountain 



