Kew Observatory. 323 



It is influenced by sun and moon, but above all it is subject to 

 sudden and abrupt fluctuations called disturbances, which are 

 invariably accompanied by auroral displays, and by electric 

 currents, which affect our telegraphic wires. The laws which 

 regulate all these motions are best discovered by means of self- 

 recording instruments, and besides investigating these, General 

 Sabine has traced from the records at Kew, and elsewhere, 

 a curious bond of connection between sun spots and magnetic 

 disturbances, two phenomena very unlike each other, but which, 

 nevertheless, have their epochs together. 



With resrard to the nature of this singular connection we 

 are yet in the dark, but we think the Kew records have thrown 

 some light upon that other bond which links together magnetic 

 disturbances, earth currents and aurora. Men of science abroad 

 are now much alive to the importance of such instruments, and 

 magnetographs similar to those at Kew are already in operation 

 at Lisbon, and will shortly be so in America and Java, in 

 Coimbra, St. Petersburg, and Florence. In illustration of the 

 value of these when all are at work together, we may state that by 

 comparing the Lisbon records with those at Kew, it has already 

 been found that maguetic disturbances break out at precisely 

 the same moment of time in both those places. 



We shall now shortly allude to the barograph, another of 

 the self-recording instruments at Kew. By it the changes in 

 the barometer are continuously recorded. Similar instruments 

 are in operation at Oxford and Greenwich, and by means of 

 these it has been found that during sudden squalls the crisis 

 of a storm takes place at Oxford about 50 minutes sooner than 

 at Kew, and at Kew somewhat sooner than at Greenwich. 

 When such instruments are more widely spread, a great in- 

 crease in our knowledge of storms may surely be expected. 



The^Kew photoheliograph is already familiar to most of us as 

 the instrument by means of which Mr. Warren Delarue succeeded 

 in obtaining photographs of the sun during the total eclipse 

 which took place in Spain on July 18, 1860, and by which he 

 proved the connection with our luminary of those mysterious red 

 protuberances which are visible on such occasions. The in- 

 strument has since been mounted at Kew under the superin- 

 tendence of this distinguished astronomer, and much curi< 

 information with regard to sun spots may be anticipated. 



In addition to all this work, monthly observations of the 

 magnetic needle are made in a small building detached from 

 the observatory, so as to be beyond the influence of iron, and 

 scientific men proceeding abroad, with the view of observing 

 the needle at various places, have an opportunity of getting their 

 instruments tested at Kew, and of their receiving instruction in 

 the science of magnetism. By this means we are not only 



vol. v. — no. v. z 



