ii METEOROLOGICAL OBSERVATIONS MADE DURING THE 



(late of the Beu Nevis Observatory) for his able assistance in the work during the past 

 two winters. 



For convenience in handling the large masses of data, this report is divided into 

 several sections. The first deals with the instruments and the mode of using them at 

 sea ; then follow the land observations made at Laurie Island, South Orkneys, a 

 meteorological log, and data from the base station at Cape Pembroke Lighthouse, 

 Falkland Lslands. The second portion of the report deals with the results of the 

 discussion of the above observations, and various maps and diagrams are appended 

 illustrative of the results. 



Observations taken at Sea. 



The form of publication of the sea observations is somewhat similar to that adopted 

 in the " Challenger " Eeport (" Narrative of the Cruise "). It comprises the readings of the 

 barometer corrected and reduced to 32° and sea-level (but not to standard gravity at 

 lat. 45°), the temperature of the air and of evaporation deduced from readings of the 

 dry and wet bull) thermometer, from which the relative humidity and vapour pressure 

 have been obtained by means of Glaisher's tables, the direction and force of the wind, the 

 amount and species of cloud, the state of the sea, and miscellaneous phenomena. The 

 position of the vessel at noon is also given. 



Atmospheric Pressure. — Barometers. 



The two barometers supplied by the Meteorological Office for use at sea were of 

 the Kew marine pattern. One (that generally in use, No. A 520) was hung in the 

 deck laboratory ; the other, A 550, in one of the saloon cabins. The corrections were 

 as follows : — 



No. 27-5 ins. 28-0 ins. 28-.5 ins. 29-0 ins. 29-5 ins. SO'O ins. 30-5 ins. 31-0 ins. 



A 520 -010 --010 --010 --010 -"OlO - 'OlO - "OlO - "OlO 

 A 550 --015 --015 --010 -"OlO -'OlO -"OlO -"OlO - 'OlO 



A note appended to A 550 indicated that in January 1902 at SO'O inches it read 

 higher than the Meteorological Office standard by '002 in. At 62° the thermometer 

 attached to No. A 520 required a correction of -0°-2, while at the same temperature 

 A 550 had a correction of — 0°-4. The barometers were compared at Buenos x\ires with 

 the standard instruments at the " Oficina Meteorological Argentina" in January 1904, 

 at the Cape Observatory in May 1904, and again at the Meteorological Office after the 

 return of the Expedition, the corrections being in substantial agreement with the above 

 throughout. Indirect comparisons were also made with the barometer at Cape 

 Pembroke Lighthouse, Falkland Islands. The mean height of the barometers above sea- 

 level was seven feet, the height varying a little according to the trim of the ship. 



A large barograph and two small ones of the usual Richard pattern were hung at an 

 approximate height of eleven feet above the sea. 



