Ixvi Introduction to the Makeestoun Observations, 1844. 



mean time of the first reading given in the third column, the reading in the fourth 

 column beinff made 60 seconds after ; thr> second column tells whether both of these 

 oliscrvations have been maile with the actinometer in the sun or in the shade ; the 

 fifth colunm gives the change of reading in (30' ; the sixth column contains the efiFect 

 of the sun in changing the reading ; the seventh column contains the mean effect 

 for a group ; and the eighth ci)lumn contains the sun's altitude for the mean time 

 corresponding to the middle of each group. 



The readings of the barometer (corrected to 32' Fahr.) and of the dry and wet bulb 

 thermometers, together with meteoi'ological remarks, are given in the foot-notes ; 

 other observations will be found in their proper places among the hourly observations. 



114. Additional meteorological notes are given after the observations of the 

 actinometer ; these consist of observations of shooting stars, thunder-storms, auroral 

 clouds, dates of flowering of plants, times of the commencement of the morning-song 

 of birds, &c. 



115. Abstracts of Results, pages 329-447. 



These Tables have appended or prefixed to them all requisite explanations, 

 together with remarks on the conclusions deduced. 



116. Curves of Term-Day Observations, <^c. 



The term-day observations, as corrected, pages 72—89, having been projected 

 and drawn with the greatest accuracy by Mr Welsh on lithographed curve paper 

 they have been transferred by the anastatic process, in 12 Plates, given at the end of 

 the volume ; the remaining plates similarly drawn and transferred are Plate XIV.^ 

 containing the projections of the daily means of the observations of the three mag- 

 netometers as given Table I., page 330, Table XXII. (in scale divisions), page 355, 

 and Table XXXVIII. (in micrometer divisions), page 373. The projected means 

 for the horizontal component exhibit the law of variation for the relative positions of 

 the sun, moon, and earth (the moon's age being the argument), in several lunations, 

 see page 358. Full moon is indicated at the head of the Plate by the symbol o, 

 new moon by . 



Plate XV. contains the projections of the diurnal ranges of the three magneto- 

 meters, from Table III., p. 335, Table XXIV. (in scale divisions), page 359, and 

 Table XL. (in micrometer divisions), page 376 : it also contains the projections 

 of the approximate daily mean disturbances for each instrument, that is, the mean 

 differences of a single observation in each day from the monthly mean for the corre- 

 sponding hour, as obtained from Table XIV., page 346, Table XXXIV., page 368, 

 and Table L., page 385. The projections on this Plate also exhibit the laws of varia- 

 tion with reference to the moon's age. 



Plate XVI. contains the projections of the hourly means for magnetical and 

 meteorological observations. The hourly means obtained from all the magnetical 

 observations are projected in continuous lines ; those obtained from the 60 days in 

 the year most free from intermittent disturbances (see page 338) are projected in 



