32 ON THE DIURNAL AND ANNUAL VARIATIONS OF 



has been postponed till at least two more years have been added to the 

 series. For a like reason, the discussion of questions relating to the 

 comparative variability of different months, and of daily means at diffe- 

 rent parts of the year, has not been undertaken. The collection of 

 suitable materials for Halifax is however in progress, as Mr. Allison 

 has been observing at equal intervals of three hours since the begin- 

 ning of 1871. 



It was stated at the commencement of this article, that besides the 

 corrections for diurnal variations, or those needed to compensate for 

 the insufficient frequency of the observations, corrections are also 

 required in order that observations taken during a few years may be 

 rendered comparable with those continued during a long series of years. 



In procuring data for the second class of corrections some other 

 observers have made considerable progress ) but in order to give full 

 effect to their past work, it is requisite that they should undertake for 

 a few years at least equidistant -observations at intervals not exceeding 

 three hours. Among these, Mr. Murdoch, C. E., of St. John's, New 

 Brunswick, who has been actively engaged in Meteorology for more 

 than ten years, is about, it is believed, to commence a system of three- 

 hour intervals. Should he persevere in this undertaking for four or 

 five years, his series will be inferior to that of no station now in corres- 

 pondence with Toronto. 



It is much to be desired also that a three-hour system could be esta- 

 blished under Dr. Smallwood, at Montreal, and Capt, Ashe, at Quebec, 

 in order that their observations in past years may be more effectively 

 utilized. 



In connection with the subject of diurnal variations it is satisfactory 

 to mention that, through the kindness of the Rev. Dr. Fyfe, President 

 of the Canadian Literary Institute, the Baptist College at Woodstock, 

 Ontario, Mr. Montgomery, the mathematical tutor, with other officers 

 of the establishment, have been engaged for some months in taking 

 observations of the temperature, day and night, at equal intervals of 

 three hours. Mr. Montgomery is fully alive to the importance of accu- 

 racy ; and as his arrangements are very excellent, it is anticipated that 

 valuable aid will be supplied by his labours towards the reduction of 

 observations in other parts of West Ontario. 



