682 Notes on Northern Caehaf. [No. f. 



Notes on the foregoing Observations. 



The instruments, by means of which these observations were taken., 

 being very imperfect ones, it is necessary to give some account of 

 them, in order to show how far the Begister may be relied upon. 



The Thermometer used, was a small one made by E. Field and 

 Son, rising to beyond boiling point of water and graduated to two 

 degrees only. Experience in reading however, easily enabled any 

 one to ascertain the height to a quarter of a degree. 



The Thermometer was hung on the eastern wall of an eastern 

 room, sixteen feet square, in a mat house. The wall consisted of a 

 double set of coarse bamboo mats, six inches apart, the interstice 

 being left vacant. The Thermometer did not touch the wall, but 

 stood three inches out. 



The room had two small windows facing the east, one of which 

 was left open night and day ; on the north and south were doors 

 leading into verandahs, and on the west to other rooms. No fire 

 was ever lighted in the room. 



The Pluviometer consisted merely of a hollow tin cylinder, two 

 and a half feet long, and four and a half inches in diameter. 



This was placed in a wooden frame, on a level piece of ground, 

 beyond the influence of houses or trees, at right angles to the earth. 

 The contents were measured every morning at 9 a. m. by means of 

 a foot rule graduated to twentieths of an inch, the depth of water 

 being easily ascertainable to the fortieth of an inch. The mean of 

 seven measurements was taken to establish each day's fall. 



Once a week the Pluviometer was tested, to prove that it remained 

 water-tight, this was done by filling it with water and enveloping it 

 in a sheet of blotting paper— a slight saturation of the paper, after 

 an hour's trial, on one occasion, showed that a leak existed, but it 

 was immediately repaired. 



No calculation has been made in this register for the evaporation 

 of water from the instrument, and considerable quantities must 

 have so disappeared, as rain has generally fallen in slight showers, 

 succeeded by hot sunshine. 



The present season is considered a remarkably dry one as far as 

 it has gone, but the drought has not affected either the spontaneous 



