CHAP. XIV.] TELEGRAPHIC MERIDIAN DISTANCE 331 



In the event of chronographs being available for recording 

 the signals received at each end, a sidereal chronometer is not 

 necessary. 



The following example of a telegraphic meridian distance Example, 

 between Penang and Singapore illustrates the case of using 

 a sidereal chronometer in connection with a mean solar chrono- 

 meter. At Singapore the time was carried on by means of 

 a sidereal standard clock, a sidereal chronometer (Mercer) 

 being used for exchanging signals. At Penang a mean solar 

 chronometer (I) was used for both purposes. 



The arrangements recently carried out for exchanging tele- Tele- 

 graphic signals over very long distances may be mentioned. Meridian 



The cable between Ascension and Porthcornow being joined Distance 

 up at the intermediate landing-point, syphon recorders with Q^eln-^ 

 two syphons were used at both ends. At Ascension one wicii and 

 syphon was connected through a battery with the chrono- Ascension, 

 meter specially fitted to record its beats on a tape, the other 

 syphon being connected with the cable. The syphons were 

 adjusted for parallax. Similar arrangements were made at 

 Porthcornow, the sidereal clock at Greenwich recording its 

 beats on the tape at the former place by means of a direct and 



