Cockayne. — Plants of Chatham Island. 251 



58° Fahr., 32° Fahr. ; July, 59° Fahr., 31° Fa*hr. ; August, 

 58° Fahr., 30° Fahr. ; September, 59° Fahr., 31° Fahr. ; Octo- 

 ber, 60° Fahr., 34° Fahr. ; November, 67° Fahr., 36° Fahr. ; 

 December, 74° Fahr., 38° Fahr. The mean daily maximum 

 temperature for a series of years ranged between 67° Fahr. and 

 60° Fahr. for January, the hottest month, and between 51 - 6° 

 Fahr. and 48 - 8° Fahr. for July, the coldest month ; similarly, 

 the mean dailv minimum ranged between 56 - 3° Fahr. and 

 48-6° Fahr. for January and 42-6° Fahr. and 38-2° Fahr. 

 for July. Such figures as the above are of very little 

 value in estimating the degree of heat to which the plants 

 are subjected, since the readings were taken in the shade. 

 On this point Mr. T. H. Kearney writes, in a recent work 

 on the vegetation of a certain island near the coast of the 

 United States (34, p. 262) : " Eeadings were taken in the 

 shade, consequently they do not represent the tempera- 

 ture to which most of the vegetation is actually exposed, 

 being subject to insolation during the hours of sun- 

 shine ; they are chiefly valuable for purposes of comparison 

 with other climates." Although the thermometer very 

 frequently falls below 40° Fahr. in Chatham Island, owing 

 chiefly to the frequency of the cold south-west wind, it rarely 

 reaches the freezing-point. The frost never exceeds 1° or 2°, 

 or perhaps double this amount on the ground ; while not un- 

 frequently there is no frost at all during the year. Some years 

 are quite without snow, in others snow has fallen on one or 

 two days ; but it usually melts as it falls, and never lies 

 on the ground for more than a few hours. Associated with 

 the frequent showers is a cloudy sky, and mists are not un- 

 common, especially in the early hours of the morning. The 

 average number of calm days during the year is only seven. 

 This fact speaks volumes as to the importance of the wind 

 factor on the plant-life of Chatham Island. The most im- 

 portant winds are the rain-bringing north-west and south- 

 west winds ; if to the former are added those marked " N." in 

 the statistics and to the latter those marked " S.," the 

 average number of days on which it blows from north-west 

 to north are 116 - 3, and on which it blows from south-west to 

 south are 139. Taking the east, south-east, and north-east 

 winds together, these blow on an average on 71 T days, while 

 the west wind blows on 283 days. 



Speaking generally regarding the climate of Chatham 

 Island, as shown by the above figures and others in the statis- 

 tics not quoted here, also from information given to me both 

 by Messrs. Cox and Shand, the climate is exceedingly mild 

 and equable — the summers are never very hot, while in 

 winter there is occasionally a very slight frost. Light 

 showers, lasting only a very short time, are frequent. The 



