562 SIR EDWARD SABINE. 



sity is greater than at Melville Island in the latitude of 74° N. In 

 his earlier report of 1837 he placed the pole of intensity in the lati- 

 tude of 52°, which is eighteen degrees south of the pole of dip. This 

 result was deduced from a magnetic reconuoissance at long range. 

 But it harmonizes with the theory of Gauss, and does not conflict 

 witlj the observations of Captain (now General Sir) J. II. Lefroy, 

 who laid cloj^er siege to it in 1843. 



In 183G, an appeal was made by Humboldt to the British govern- 

 ment to establish at various places in its vast empire magnetical obser- 

 vatories similar to those then operating in Germany and Russia. 

 Accordingly, in 1839-40, four of these observatories were instituted ; 

 viz. at Toronto, St. Helena, the Cape of Good Hope, and Ilobarton. 

 They were not intended to be permanent ; and the jieriod of their 

 activity varied from three to ten years. Their work was reinforced 

 by the Naval Scientific Plvpedition to the Antarctic Zone of Sir J. 

 C. Ross and Lieutenant Moore. The observers were selected largely 

 from the younger officers of the Horse- Artillery, and were instructed 

 in their new work by Professor Lloyd at Dublin. It is sufficient to 

 say that most of them acquired a scientific taste and reputation which 

 introduced them to the Royal Society, while they have also risen to 

 the highest rank in their profession. The appointment of Major 

 Sabine as the general superintendent of this great scientific work was 

 fortunate. He devoted twenty years of his life to the arrangement, 

 discussion, and publication of the formidable mass of meteorological 

 and magnetical observations which issued from these prolific observa- 

 tories. Only a brave heart would have confronted this stupendous 

 task, even with the liberal clerical aid furnished by the government. 

 In the voluminous introductions to the twelve thick quarto volumes 

 which issued from his office, Sabine investigated the periodical changes 

 in the meteorological and magnetic elements, their secular variations, 

 their irregular fluctuations, their relations to solar and lunar time, 

 to disturbances in the sun, and to the aurora. The decennial period 

 in the amplitude of the diurnal oscillation of the needle, which Lament 

 detected in his observations at Munich, reappeared in Sabine's mate- 

 rials, and was extended to the irregular disturbances, and later, by 

 himself and others, to changes in the declination, dip, and intensity. 

 Ilansteen, from a larger scries of observations, changes the period to 

 eleven years. Meanwhile, AV^olf had deduced from Schwabe's cata- 

 logue of solar spots a similar period in their number and magnitude 

 About 1852 came the interesting announcement by Sabine, Wolf, 

 Secchi, and Gautier, of a probable coincidence in the maxima of spot- 



