62 



2d. — Dunleith signals recorded at both stations. 



Times of 



signals given at sig 



Dunleith 



hj sidereal 



Chronometer 



No. 2557. 



h. m. s. 

 10 28 18 

 10 31 18.5 

 10 34 19.0 

 10 43 20.5 

 10 46 21 



2d Mean. — Electric signals sent from Dunleith to Chicago, 

 1st Mean. — Electric signals sent from Chicago to Dunleith, 

 as above, --_______ 



Result: — Dunleith Station No. 1, is west, in longitude of Chi- 

 cago obsei'ving Station No. 3, by a mean of the two sets of 



Difference of 

 Longitude by 

 each signal. — 

 Dunleith west 

 of the meridian 

 of Chicago ob- 

 serving station 

 No. .3. 



h. m. s. 

 12 04.69 

 12 04.69 

 12 04.70 

 12 04.71 

 12 04.71 



12 04.70 



12 04.673 



siffuals. 



Longitude of Chicago observing station No. 3, west 

 of the meridian of Greenwich, 



Determination 1st. 



Longitude of Dunleith observing station, west of the 

 nneridian of Greenwich, 



— 12 04.086 



+ 5 50 31.20 



6 02 35.^ 



For the second determination, reference must be had to the time- 

 observations at Dunleith, of the 22d of February; and to those at 

 Chicago, as before slated, of the 20th and 23d of February, and to 

 the following telegraphic signals, viz. — 



Detei'inination of the difference of Longitude between Chicago and 

 Dunleith, Illinois, by electric signals for comj)arisons of time, 

 February 22, 1859. 



Sidereal Chronometer No. 2557, fast, of Dunleith sidereal time, 

 (at 10/i. 00m. sidereal time), \h. 38m. 205.51. 



Rate per sidereal day, + 5^.308; or per sidereal hour, + 05.221. 



Mean solar Chronometer No. 141, slow, of Chicago, mean solar 

 time, (at I2h. 01m. 425. mean time), 4m. 42s. 92. 



Rate per mean solar day, — 05.746; or per mean solar hour, — 

 05.03109. 



