Fig, 91. HENLEY'S MAGNETIC NEEDLE TELEGRAPH. 



THE ELECTRIC TELEGRAPH. 



CHAPTEE XIII. 



266. Signal time balls. 267. Electric connection of observatories of Green- 

 wich, Brussels, and Paris. 268. Uses of electric telegraph in astro- 

 nomical observations. 269. In regulating the observatory clocks. 

 270. In fixing with precision the time of an astronomical phenomenon. 

 271. Telegraphic lines of the United Kingdom. 272. Their extent 

 in 1854. 273. Electric Telegraph Company. 274. Table of its lines, 

 stations, &c. 275. Present tariff (1854). 



266. Br concert between the Astronomer Royal and the several 

 Electric Telegraph Companies, the Greenwich local time is 

 announced at certain hours of the day, at conspicuous places in 

 different parts of the country, so that navigators who happen to 

 be in any of our ports, may avail themselves of these means of 

 regulating their chronometers. "We have already explained the 



LARDNER'S MUSEUM OF SCIENCE. H 97 



No. 50. 



