V 



give way, and during a stay at Lynton (Devonshire) he had, in 1878, 

 a kind of nervous attack, which was the beginning of his last illness. 

 He died suddenly on the 22nd November, 1879. 



If Broun occupied the position of a leading pioneer in observa- 

 tional inquiry, he also shared the discomforts of such a post. He 

 considered no trouble too great in order to procure trustworthy 

 observations, and he would spend an immense amount of labour upon 

 them, when once obtained. On one occasion, with the purpose of 

 making observations, he lived for about six weeks in a hut on the 

 Cheviot Hills, performing his toilet in the open air, sometimes with 

 mists around him and water nearly freezing. 



It has been said of Faraday that his failures must have cost him 

 even more thought than his successes, and the same remark will apply, 

 with even greater force, to an original thinker in observational science 

 like Broun. Here the testing of every idea entails a laborious in- 

 vestigation, and Broun, whose mind was at once very fertile and very 

 scrupulous, must often have overworked himself before dismissing 

 a subject from his thoughts. It seems likely that this combination of 

 qualities eventually contributed to undermine his health. 



During the latter part of his life he received from the Government 

 Fund of the Royal Society a sum of money to enable him to improve 

 and complete the reduction of the colonial magnetic observations. 

 But this immediate and apparent responsibility was peculiarly trying 

 to a man like Broun. The work seemed to go on growing the more he 

 examined it, and he was never satisfied without going still more deeply 

 into the subject than he had already gone. At length his health began 

 to give way, and the thought that he had not been able to finish these 

 investigations unfortunately hastened the progress of his malady. 



It must not be supposed that Broun, while combining scrupulosity 

 and intense devotion to science, was by nature a recluse. He was, on 

 the contrary, a man of delicate social instincts and well calculated to 

 take an active part in scientific administration. His deafness, however, 

 prevented this, and during the latter years of his life he was best 

 known to a small, but attached, circle of friends. 



Broun was both a magnetician and a meteorologist. His Makerstoun 

 observations have been already mentioned as being peculiarly valuable 

 for the light they threw, at a comparatively early period, on the 

 changes of the magnetism of the earth. 



In 1861 he contributed two very valuable memoirs to the " Transac- 

 tions of the Royal Society of Edinburgh." In one of these he discussed 

 the errors and corrections of the bifilar magnetometer, including the 

 determination of its temperature coefficient, which he showed might 

 be found by a more correct method than that hitherto adopted. His 

 second memoir was on the horizontal force of the earth's magnetism, 

 for which he established the annual laws from a discussion of observa- 



