580 



Prof. B. Stewart on the Daily 



6. The dates of minimum and maximum spot frequency, as given by 

 Messrs. De La E-ue, Stewart, and Loewy, in the above-mentioned paper 

 are as follows :~ 



Minimum April 1856, 



Maximum September 1859, 



Minimum February 1867 ; 



(to which we may add) — 



Maximum Somewhere in 1870 ? 



Minimum Somewhere in 1875 ? 



taking yearly periods, Table II. gives corresponding fluctuations as fol- 

 lows : — 



Minimum January 1856, 



Maximum July 1859, 



Minimum May. 1866, 



Maximum October 1870, 



Minimum Probably end of 1875*. 



7. If we still regard it as most likely, though not proven, both from 

 the evidence herein recorded and from collateral considerations, that there 

 is some connexion between the daily temperature-range and the state of 

 the sun with regard to spots, then we may suppose that the redundant 

 temperature-oscillation between 1859 and 1866, already alluded to, is a 

 local phenomenon which will disappear when a sufficient number of sta- 

 tions are discussed. There would seem, however, to be another possible 

 mode of explaining the circumstance, and allusion will be made to this in 

 another part of this paper (art. 17). 



C. Lunar Annual Variation. 



8. It will be of interest to determine whether the temperature-range 

 has any reference to the relative position of the sun and moon. Por this 

 purpose the whole period of observation has been portioned out into lu- 

 nations, beginning with new moon. Each lunation is divided into 8 parts, 

 entitled :— (0), (1), (2), (3), (4), (5), (6), (7)— (0) denoting new and (4) 

 full moon. 



The various lunations with the corresponding values of the tempera- 

 ture-range are exhibited in Table III. It will, however, be here neces- 

 sary to state how these values have been obtained. Take the dates (civil 

 time) of the four quarterly phases of the moon as given by the Nautical 

 Almanac, and under each of these dates, as a centre, group seven ob- 

 servations. Each value in Table III. corresponding to (0), (2), (4), (6) 

 is thus the mean of seven separate observations of daily range. 



* This is only a rough comparison, and must not be regarded as indicating that 

 meteorological phenomena precede certain corresponding solar phenomena with which 

 they are supposed to be connected, — [Added March 5, 1877.] 



