IN THE ARCTIC SEAS. 



The north end of the level was always read first ; the temperature of the air, and 

 the barometer and attached thermometer readings, are taken from the meteorologi- 

 cal record, and discussed by me in 1859 (see Smithsonian Contributions to Know- 

 ledge, vol. XI, Farts I and III, of the Meteorological paper). 



Thermometer + 22°. 6 Fahr. Approximate latitude + 78° 37' 12". 



Barometer 29.70 inch. Approximate longitude 4'' 43™ 28" west of Greenwich. 



Attached thermometer 66°. From a preliminary discussion of the moon culminations. 

 Time is noted by the pocket chronometer. 

 We find : Reading of O's centre, corrected for level . 



O's apparent zenith distance 

 Correction for refraction .... 

 " for parallax .... 



O's corrected zenith distance 

 Hence, by the usual formula : — 



Apparent time of observation . 

 Equation of time ..... 



Mean time of observation . . . . . 22 28 12.3 

 Chronometer time of observation . . . . 27 11 38.2 



Pocket chronometer fast of Fern Rock mean time . 4 

 (Hence this chronometer indicates very nearly Greenwich mean time.) 



43 25.9 



