449 



west ; the minimum at the ship, 7 - 6 F., was registered on the 6th, when there was a gentle breeze from 

 east. The average direction and force of the wind is found from Captain SCOTT'S observations to have 

 been south-west by south, 1 7, while at the ship the prevailing direction and force was east, 2. The 

 travellers had a clear sky on 8 days ; a cloudy, or overcast, sky on 7 ; snow on 3 days ; fog on 5. At the 

 ship the sky was clear on 7 days ; cloudy, or overcast, on 8. Snow fell on 4 days, and the weather was 

 foggy on 3 days. 



Referring to the snowfall on the plateau in his book, ' The Voyage of the " Discovery," ' Captain SCOTT 

 says: "The layer sandy layer of loose ice-crystals grew heavier as we approached the edge of the 

 plateau; this was an interesting observation, for it shows that the plateau snowfall takes place in 

 December and that it is far heavier on the edge than in the interior of the continent. Another interesting 

 fact was observable, in this connexion, for while the light snow had been falling the wind had crept round 

 to the south, sometimes to such an angle with our course that it was difficult to trim our sledge sail to 

 derive any benefit from it. In the most southerly direction it brought a desirable increase of temperature, 

 and on some days we had a fair imitation of the mild southerly blizzards which were such a conspicuous 

 feature at the ship." 



This rise of temperature with south winds and snowfall on the plateau appears to be connected with 

 the passage eastward of low-pressure systems, having their centres over the sea, whence the milder air was 

 drawn, and these concurrent conditions go far towards proving the truth of the surmise that the rise of 

 temperature in the southerly gales experienced at Winter Quarters, usually associated with snow, was not 

 due to Fcihn effect, as has been generally supposed, but to the wind's origin in warmer latitudes. The 

 southerly snow-bearing winds of the plateau and the ice barrier alike probably owed their relatively high 

 temperature and humidity to their place of origin in lower latitudes and belonged to cyclonic wind systems 

 that had their centres situated far out at sea. 



A journey was made by Lieutenant ROYDS and party to the south-east, across the ice barrier, in November Lieuienant ROYDS to 



and December, 1903, which yielded interesting results for comparison with meteorological conditions at ^nber^nd Dec" 



Winter Quarters. Lieutenant ROYDS left the " Discovery " on the 10th November, and between this date ember, 1903. 



and the last day of the month, when he was in latitude 79 20' S., longitude 174 32' E., the mean of the 



observations for temperature is found to be ll'l F., while that at Winter Quarters comes out as 17 '7 F. 



The maximum temperature during these days, 25 -5 F., was observed on the llth, in a calm; the 



maximum at Winter Quarters, 34 F., was registered on the 22nd, also in a calm. The minimum tempera- 



ture, -12 '6 F., was observed on the loth in a calm; the minimum at Winter Quarters, -2 '2 F., 



occurred on the 19th, when there was a light breeze from south-east. The average wind direction and 



force, as recorded by Lieutenant ROYDS, is found to have been south-south-west, 2 ; at Winter Quarters it 



was east-south-east, 2 4. The sky was clear for 3 days on the barrier, for 4 days at the ship ; cloudy for 



7 days on the barrier, for 1 1 days at the ship ; overcast for 1 1 days on the barrier, for 6 days at the ship. 



Snow fell on 4 days at the barrier, on 7 days at the ship ; fog was experienced on 5 days on the barrier, 



on 2 days at the ship. 



Lieutenant ROYDS arrived at his most southerly and easterly position on the 28th, when he retraced his 

 steps. From the 1st to the 10th of December, inclusive, between his position on the last day of November 

 and that of the ship, the mean of the observations for temperature is 16 0- 4 F., against 21'8 F., the mean 

 temperature at the ship during the same time. 



The maximum temperature of 24 -5 F. was observed on the 2nd of the month, the wind being light 

 from south-west at the time; the maximum temperature at the ship during the same period, 32' 2 F., 

 was registered on the 10th, when there was no wind. The minimum reading taken on the barrier during 

 these 10 days, - 3 F., is noted on the 4th, and again on the 6th, with gentle breezes from south-west ; 

 the minimum at the ship, 7 '6 F., was recorded on the 6th, with a moderate breeze from east. 



The average wind direction and force, as estimated by Lieutenant ROYDS, was south-west by south, 1 7, on 

 the barrier ; at the ship it was east by north, 2 -3. During the period the sky was clear for 4 days, cloudy 

 for 4 days, and overcast for 2 days on the barrier ; clear for 3 days, cloudy for 5 days, and overcast for 

 2 days at the ship. On the barrier, snow was experienced on 3 days, fog on 4 days ; while at the ship 

 there was snow on 4 days and fog on 3. 



3 M 



