METEOROLOGY. 



EXPLANATORY NOTES REGARDING THE TABLES OF OBSERVATIONS 



(Pp. 17-272). 



THE data contained in the tables of Meteorological Observations have been arranged as follows : 



Column 1 . Hour. The hour at which the observations given in the succeeding columns were made. 



Column 2. Barometer. The barometer was hung on board the " Discovery," where its cistern was 

 9 feet above the level of the sea. The readings have been corrected for instrumental error and reduced 

 to sea-level and to 32 F., but have not been corrected for gravity. The mean of the bi-hourly readings 

 made each day is given at the foot of the column. 



Column 3. Cape Armitage. The temperature of the air in degrees Fahrenheit observed at a point 

 off Cape Armitage about 3000 yards south-south-east of the " Discovery." The thermometer used was a 

 spirit minimum thermometer, supported upon a light wooden stand at a height of 4 feet above the snow, 

 and freely exposed to the air. Throughout the summer months the supporting frame was covered by a 

 wooden awning to protect the thermometer from the sun's rays, but during the winter months the awning 

 was removed and the bulb left open to the sky. The reading of the thermometer at the time of observa- 

 tion as well as the minimum temperature shown by the index was recorded at each observation. 



Column 4. Spirit Minimum. The minimum temperature of the air recorded by a spirit minimum 

 thermometer placed in a screen about 120 yards from the ship. The thermometer was read and set every 

 two hours. The following corrections have been applied to the readings of this thermometer : 



Correction. 



When the temperature was above - 5 F 0'0 



was - 5 F. and not below - 15 F +0'5 



was below - 15 F +1'0 



Column 5. Dry. The temperature of the air in degrees Fahrenheit, obtained from a mercurial 

 thermometer exposed in the same thermometer screen as the minimum thermometer, at a height of 4 feet 

 above the snow. No correction for instrumental error has been applied to the readings of this thermo- 



B 



