18 SCOTT. — METEOEOLOGIOAL INSTRUCTIONS. 



supplied, which should be erected on a high pole, or on the mast- 

 head when the ship is in winter quarters. The description of this 

 instrument and its management and registration will be supplied 

 with it. 



Two small anemometers are also supplied ; these must be read 

 at least once daily. 



Clouds. — The directions for observing clouds are contained 

 in the ordinaiy Instructions for Observers at Sea, but there are 

 certain observations of much interest which may be made on clouds 

 as indicating the motion of upper currents in the atmosphere. 



It is therefore of importance that, whenever possible, the direc- 

 tion and apparent rate of motion of the different strata of clouds 

 should be recorded, whether these agree with the wind at the 

 surface of the earth or not. 



There is especial interest in the question of the motion of the 

 upper clouds near the region of greatest cold, as it is believed by 

 most meteorologists that these upper currents flow towards the 

 districts of great cold, where the air descends to the surface of the 

 earth. 



Hydrometeors or Weather Observations. — These should be re- 

 corded as directed in the *' Instructions in the Use of Meteorological 

 Instruments," of which copies are supplied to the Expedition. 



As regards the Aurora, Prof. Stokes has furnished certain notes 

 which are appended to these instructions. The greatest care 

 should be taken to note and register the most striking particulars 

 as to its appearance and modifications, especially as to its manifes- 

 tations in any quarter as regards the existence of open water, &c., 

 in that direction. The subject of magnetic observations or of 

 spectroscopic examination of the Aurora does not fall within the 

 scope of meteorological observations. 



As regards Halos, Parhelia, and Paraselense, &c., the variety in 

 these appearances is so great that no definite rules can be laid 

 down for observing them. The phenomena observed should be 

 carefully sketched, and wherever possible measurements should be 

 taken by sextant. 



In conclusion, the attention of the observers should be specially 

 directed to the fact that many of the storms which pass over the 

 extreme north of Europe are connected with areas of barometrical 

 depression which follow tracks lying within the Arctic Circle ; they 

 have been traced almost wherever the whaling and sealing ships 

 have advanced between Spitzbergen and Greenland, and there is 

 reason to believe that they will be observed at the head of Smith 

 Sound also. 



It will therefore be a matter of the greatest interest to notice 

 whether or not these areas of barometrical depression appear to 

 be formed near the spot where the Expedition is in winter 

 quarters.' 



At all times of sudden barometrical oscillations the observations 

 should be made as frequently as possible, as by this means it may 

 be rendered possible to ascertain whether the centre of the disturb- 

 ance has passed north or south of the ship. 



