252 



Abstracts of the Makerstoun Observations, 1843. 



TABLE XXN .—Continued. 



Period. 



ISh. 



20i. 



22". 



231'. 



0\ 



21'. 



4". 



et. 



Sb. 



lOh. 



Range. 





0.000 



0-OUO 



0-000 



0-000 



0-000 



0-000 



0-000 



0-000 



0-000 



0-000 



o-ooo 



October 



000 



052 



035 





040 



167 



282 



279 



206 



136 



282 



November 



000 



014 



005 



-on 



009 



120 



175 



150 



133 



097 



175 



December 



000 



016 



004 



-006 



026 



086 



176 



165 



196 



095 



196 



Spring 



024 



079 



039 





000 



078 



219 



378 



339 



196 



378 



Summer 



118 



148 



065 





000 



116 



307 



423 



446 



254 



446 



Autumn 



016 



076 



040 





000 



155 



285 



325 



261 



153 



325 



Winter 



000 



027 



014 





031 



107 



157 



155 



163 



112 



163 



Winter Solstice 



000 



040 



018 





029 



097 



156 



165 



177 



123 



177 



Equinoxes 



013 



069 



036 





000 



115 



260 



370 



296 



157 



370 



Summer Solstice 



112 



145 



069 





000 



135 



315 



432 



438 



262 



438 



The Year 



1 



032 



075 



031 





000 



106 



234 



313 



294 



171 



313 



Diurnal Variation op the Total Magnetic Force. 



Spring, in the foregoing table, consists of the months of February, March, and April. 

 The diurnal curve is double in each month of the year. In the mean for the year, — 



The principal maximimi occurs about &^ p.m., Makerstoun mean time. 



A minimum occurs about \V^ 10™ a.m., 



A secondary maximum occurs about 1^ 10™ a.m., 



A minimum occurs between 9** p.m. and 5^^ a.m., 



These observations do not shew the period of this minimum, nor whether it is secondary or principal. 



The principal maximum occurs as late as 7*^ p.m. in winter and in summer, and as early as 4** and b^ p.m. 

 in some of the months about the equinoxes. The secondary maximum occurs at the same hour, 1'^ 10™ a.m., 

 throughout the year. In the winter months, the principal minimum occurs between ^^ 10™ p.m., and b^ 10™ 

 a.m. The minimum near noon occurs about 9*^ 40™ a.m. in mid-winter, and about 11^10™ a.m. in mid-summer. 

 The follomng table has been formed in order to obtain, if possible, the period of the earliest minimum. 



TABLE XXVI. — Diurnal Variations of the Total Force of the Earth's Magnetism, deduced from 



Tables XII. and XIX. 



Gbtt. 



Winter 





Summer 





Giitt. 



Winter 





Summer 





M. T. 



Solstice. 



Equinoxes. 



Solstice. 



Mean. 



M.T. 



Solstice. 



Equinoxes. 



Solstice. 



Mean. 



H. 



0-000 



0-000 



0-000 



0-000' 



H. 



0-000 



0-000 



0-000 



0-000 



10 



213 



600 



281 



355 



22 



081 



397 



168 



206 



11 



152 



509 



260 



298 



23 



077 



375 



120 



181 



12 



045 



413 



177 



202 







102 



378 



104 



186 



13 



000 



010 



049 



Oil 



1 



160 



398 



133 



221 



14 



029 



000 



000 



000 



2 



197 



443 



257 



290 



15 



071 



045 



006 



031 



3 



214 



535 



331 



351 



16 



064 



014 



046 



032 



4 



240 



649 



389 



417 



17 



044 



148 



145 



103 



5 



237 



698 



418 



442 



18 



062 



278 



169 



161 



6 



216 



744 



460 



464 



19 



096 



382 



209 



220 



7 



195 



726 



503 



465 



20 



090 



444 



188 



231 



8 



180 



622 



506 



427 



21 



106 



461 



188 



242 



9 



168 



533 



475 



383 



