470 



MR J. Y. BUCHANAN ON THE 



take off the values for one time as for another. It is certain that it is apparent time 

 and not any conventional time that rules meteorological phenomena. 



Winds. — Only the direction of the wind is given in the tables. In foggy weather 

 the prevailing directions are N., N.W., W., and S.W., the greatest percentage being 

 from the West. In clear weather the prevailing directions are N., S.E., and S., with 

 a maximum at S.E., while calms occur very frequently. The cyclonic gales so common 

 on our coasts, especially in winter, blow hardest between S.W. and N.W., and on 

 these occasions the summit is usually enveloped in fog. On the other hand, in anti- 

 cyclonic weather the air has hardly any sensible horizontal motion, and is generally 

 clear and warm. 



In the following short table are given the general results of the classification of 

 the winds according to percentage, and distributed over eight points of the compass : — 



Weather. 



N. 



N.E. 



E. 



S.E. 



S. 



S.W. 



W. 



N.W. 



Calm. 





Clear . 



Foggy . 



17-45 

 16-88 



6-01 

 5-28 



11-63 

 3-63 



18-85 

 5-64 



16-74 

 6-95 



8-94 

 17-82 



6-17 

 23-72 



3-54 



16-65 



10-67 

 3-43 



100 

 100 



If the winds were equally distributed round the compass we should have 12 '5 per- 

 cent, from each point. In clear weather the amounts are above the average for N., 

 S.E. and S. ; in foggy weather, they are above the average for S.W., W., N.W. and 

 N. ; the maximum falling on W., with 2372 per cent., and the minimum on E., with 

 3*63 per cent. 



Rainfall. — In continuous foggy weather there is always some precipitation measured, 

 and it is usually very abundant. There is only one spell of foggy weather in which 

 no precipitation was registered, and that was January 1897. In continuous clear (not 

 necessarily cloudless) weather it may be said that it never rains at all. The only 

 exception which could be taken to this might be the cases of June and August. In 

 June, in the 2895 selected hours, the total amount of rain measured was 1*243 ins., 

 giving an average of one hundredth of an inch in twenty-four hours. In August, in 

 the 971 selected hours, 0'72 in. fell, giving an average of 0'018 in. per twenty-four 

 hours. There are only five occasions in the course of the thirteen years when more 

 than one-tenth of an inch of rain fell during the clear weather of any one month, and 

 the chief of these are 0*685 in. in August 1890, and 0*298 and 0*774 in. in June 

 of 1887 and 1893 respectively. Two-thirds of the whole rain fell in these five months, 

 the remaining third is distributed over forty months, and 111 months out of the total 

 of 156 have none at all. 



If we now turn to foggy weather, we see a very different state of things. As 

 already pointed out, there is only one spell of foggy weather where no rain or pre- 

 cipitation has been measured. The smallest mean daily rainfall in foggy weather is 



