70 THE VOYAGE OF H.M.S. CHALLENGER. 



abnormal weather over the whole globe. If a line be drawn from Texas to Newfound- 

 land, across the Atlantic, the north of France and Germany, thence round by south- 

 east through the Black Sea, the Caucasus, India, the East Indian Islands, and 

 Australia, to the south of New Zealand, it will pass through a broad extended region 

 where pressure was throughout considerably below the mean of December, and this 

 prolonged area of abnormally low pressure was still further deepened in various regions 

 along the line. Another line passing through the Philippine Islands, Japan, Manchuria, 

 Behring's Straits, and Alaska marks out another extensive region where pressure was 

 uninterruptedly below the mean. 



On the other hand, pressure was above the average of the month, and generally 

 largely so, over the United States to west of longitude 90°, over Greenland, Iceland, 

 the Faroes, Shetland, and a large part of the Old Continent, by a line drawn from 

 Finland round by Lake Balkhash, Canton, and Pekin, to the upper region of the Lena. 

 Another area of high pressure extended from Syria through Egypt and East Africa to 

 the Cape ; and part of a third area of high pressure was seen in the North Island of 

 New Zealand. 



As regards North America, the greatest excess of pressure, about 0'20 inch above 

 the mean, was in the valley of the Columbia, from which it gradually fell on proceeding 

 eastwards to a defect from the mean of 0'15 inch near Lake Champlain and to north- 

 ward, rising again to near the mean in the north of Nova Scotia. To the north and 

 north-east exceedingly high pressures for these regions and for this month prevailed, 

 being 0"635 inch above the mean in Iceland, 0'50 inch in the south of Greenland, the 

 excess diminishing on advancing northwards along West Greenland. 



West Greenland being thus on the west side of the region of high pressure, which 

 for the time overspread the northern part of the Atlantic, and on the north-east side of 

 the area of low pressure in the United States and Canada, strong south winds set in 

 along that coast, and the temperature at the four Greenland stations, proceeding from 

 south to north, rose to 1 0, 1, 8°'8, 12°"1, and 14° - 4 above the means, being in accordance 

 with the relations of the distribution of pressure and temperature everywhere shown to 

 prevail by the mean pressure and temperature charts of the months. Again, as the 

 centre of lowest pressure was about Montreal, strong northerly and westerly winds 

 predominated to westward and southward, and consequently temperature was there 

 below the average, the deficiency at St. Louis and Chicago being 9° - 5 ; and the winds 

 being northerly and easterly in California, temperature was there also under the mean. 



On the other hand, in the New England States, the greater part of the Dominion 

 of Canada and West Greenland, temperature was above the average. Pressure was 

 much higher at St. Michael's, Alaska, than at St. Paul's to south-westward ; and hence 

 while temperature at St. Paul's was 2° - 9 below the normal, it was 12° - above it at St. 

 Michael's, where strong winds from the south prevailed. 



