APPLICATION OF THE ELECTEIC TELEGRAPH. 345 



APPLICATION OF THE ELECTRIC CIRCUIT TO ASTRONOMICAL 

 USES IN EUROPE. 



In December, 1849, the astronomer royal of England 

 communicated to the Koyal Astronomical Society a 

 detailed account of "the method of observing and re- 

 cording transits lately introduced in America;" and he 

 concluded his narrative by stating that the possible advan- 

 tages of this method appeared so great, that he had begun 

 to contemplate the practicability of adopting it in the Koyal 

 observatory. He proposed to record the observations 

 upon a cylinder, perhaps revolving upon a screw axis ; 

 and suggested that great convenience would be gained 

 if the movement of the cylinder could be made so per- 

 fectly uniform that it could be adopted as the transit 

 clock. He, therefore, urged strongly the importance of 

 improvements of the centrifugal or conical pendulum 

 clock, as the only instrument yet made which is able to 

 do heavy work with smooth motion, and with an ac- 

 curacy at present so great as to make it probable that, 

 with due modification, the greatest accuracy may be ob- 

 tained. 



In June, 1853, Professor Airy reported that owing to 

 various delays his apparatus was not yet brought into 

 use ; but that he had brought it to such a state, that he 

 was beginning to try whether the barrel moved with suffi- 

 cient uniformity to be itself used as the transit clock. 



The first transits recorded by the electric method at 



Greenwich were made on March 27, 1854, and since that 



15* 



