ASTRONOMY AND METEOROLOGY. 307 



fourth octant, or fourth day, after full moon. In the same years there were 

 also, amongst many others, the following remarkable instances of reciprocity 

 between opposite phases of the moon : In December the minimum for the 

 month occurred on the third day before neAV moon ; in January the maxi- 

 mum on the third day before full moon ; in February the minimum on the 

 third day before new moon. And again, the maximum in September fell 

 on the day after full moon. The minimum in October on the day after new 

 moon. " In addition to this, the maxima and minima for the month were 

 found to occur at intervals of rather more than seven, fourteen, or twenty- 

 one days, and that for several successive months, viz., April, May, June, 

 August, and September, and so in other years." In 1838, exactly ten years 

 earlier, maxima or minima occurred three times on the third day after neAV 

 moon; three times on the day after full moon; three times on the day of 

 first quarter; and three times on the day of last quarter: that is to say, in 

 twelve instances out of twenty-four on four days of the lunation. At the Cape 

 of Good Hope, reciprocity of action and the recurrence of high and low tem- 

 peratures were even more frequent and systematic. Thus, in 1855, eight out 

 of the twelve maxima for the month occurred at first quarter, and nine of the 

 twelve minima at new or full moon. In 1842, nineteen maxima and minima 

 out of twenty-four, occurred on eight days. In 1843, fifteen on seven days; 

 in 1814, seventeen on six days ; in 1845, eleven on four days. The recur- 

 rence of maxima and minima at Toronto and Madras was equally marked. 

 Mr. Harrison considered that the dispersion of clouds under full moon may 

 now be taken as a fact, on the testimony of Humboldt, Sir J. Herschel, Mr. 

 Johnson (the Radcliffe observer at Oxford), and others. Mr. Johnson hav- 

 ing also noticed that this cloud-dispelling power commences about the fourth 

 or fifth day of the moon's age, and lasts till she approaches the sun, the 

 same distance on the other side ; that is to say, the influence takes place at 

 that time as well as at full moon, though not necessarily continuously. Mr. 

 Kasmyth also, who was considered a valuable witness, from his long-con- 

 tinued observation of the moon for the purpose of mapping its surface, was 

 quoted as having satisfied himself that clouds disappear when the moon is 

 about four days old; and also, that when this is the case for any length of 

 time at new moon, the sky is clouded to a corresponding extent at full moon, 

 another instance of the principle of reciprocity. Several well-known ob- 

 servers were also mentioned, as having noticed the remarkable clearness of 

 the 7norning of the 13th of September, or the fifth day after new moon. And 

 lastly, even M. Arago's explanation of the popular notion among gardeners 

 round Paris, that the moon which, commencing in April, becomes full in 

 May, destroys their tender plants, it was thought might be quoted as evi- 

 dence of lunar influence on the atmosphere, though given by him as a simple 

 statement of the effects of terrestrial radiation on early vegetation. Mr. 

 Harrison, in conclusion, expressed his belief that the remarkable regularity 

 of the recurrence of a fall before first quarter, is due to the clearing of the 

 atmosphere at that period, and the rise after first quarter to a more cloudy 

 state of the sky. That the same effect is not so evident on the curves at the 

 period of full moon, he considered might be due to the greater reciprocity 

 of action which takes place at the syzygies, or new and full moon. 



The President, Mr. Hopkins, observed, that the facts Mr. Harrison had ad- 

 duced, must be considered strongly confirmatory of the view he so ably 

 advocated. That the moon exercised an influence upon the weather, and 

 particularly on the formation or dispersion of clouds, was, as all knew, a 



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