330 HISTORY OF ASTRONOMY. 



. OBSERVATIONS FOR LONGITUDE SINCE THE AUTUMN 



OF 1848. 



On the 17th of November, 1848, Professor Locke, at 

 Cincinnati, undertook so to connect his clock with the 

 telegraph line that 'its beats should be heard and regis- 

 tered at Pittsburg, a distance of about four hundred 

 miles. The circuit was broken every second at Cin- 

 cinnati by the motion of the clock ; and at Pittsburg, 

 the fillet of paper being allowed to run off from the reel 

 of the telegraph register, it was graduated into equal 

 portions, consisting of an indented line about nine-tenths 

 of an inch in length, followed by a blank space of about 

 one-tenth of an inch. The two correspond to one second 

 of time, commencing with the beginning of the line. 

 This experiment was continued for two hours, during 

 which time the seconds of the Cincinnati clock were 

 registered on the running fillet of paper at all the offices 

 along the line. In order to distinguish the hours and 

 minutes upon this graduated paper, Dr. Locke proposed 

 to make the beginning of the ordinary minutes omit 

 one blank space ; the beginning of five minutes omit two, 

 of ten minutes three, and of an hour omit four con- 

 secutive blank spaces. Thus, ordinary beginnings of 

 minutes have continuous lines of two seconds, fives three, 

 tens four, and hours Jive seconds. 



*, In the month 'of January, 1849, a clock upon Dr. 

 Locke's construction was employed for printing transits 

 of stars over different meridians for the determination 



