ALLISON FLUCTUATION OF THE BAROMETER. 157 



pinnules laciniately divided into narrow teeth. Habs. — Mt. Uniacke, 

 (Rev. J. B. Uniacke) ; New Germany, roadside between Barss' 

 Corner and the LaHave, Lunenburg Co., (Rev. E. H. Ball.) 

 The two varieties seem to be rare. 



Art. VI. — The Semi Daily Fluctuation of the Barometer. 

 By Frederick Allison. 



(Read before the Institute, May 8th, 1876.) 



Before proceeding to an investigation of this phenomenon — well 

 known to observers — I wish to offer a few remarks upon the 

 weather of last year, a summary of which you have in the General 

 Register before you. 



In 1875 we had a cool year — the coldest at least since 1859, if 

 not for a longer period. The normal temperature in Halifax is 

 42°. 66. This year was 40°. 23. We may notice here the very 

 small difference in yearly mean heat. However great may be the 

 ranges in the twelve months — last year they extended over 99° and 

 sometimes they reach 104°, as in 1866 — so well balanced are the 

 several months and seasons that 4°. 27 will cover the means of the 

 last 16 years. August was the only month which ran above its 

 normal, and was much the hottest month of the year. The maxi- 

 mum heat also occurred in this month 85°. Many months were 

 cold, but January was excessively so ; its mean 14°. 99 being 7°. 7 

 below its normal, and this was the coldest month I ever experi- 

 enced in Nova Scotia. February — mean 17°. 99 was also very 

 cold; and then we touched the minimum — 14°. The 15th of 

 August was the warmest day ; and the day exactly six months 

 earlier, the 15th of February was the coldest. The 3rd of June 

 was a very remarkable day in temperature. At 4 a. m., the ther- 

 mometer was 34°. 5 and before noon had mounted to 72°. 8 — 

 giving the enormous range of 38°. 3 within 8 hours. The pressure 

 was a little more than usual, slightly exceeding the normal in every 

 month, but especially in August. The maximum was on the 23rd 



