252 ABSTRACTS OF THE MAKERSTOUN OBSERVATIONS, 1843. 
TABLE XXV.—Continued. 
Period. ) 18h. | 20%, | 22h, | 23h, : 2h, 4h, : : . || Range: 
0.000 0-000 0-000 0-000 0-000 0000 5 0-000 
October 052 167 282 282 
November —011 120 175 175 
December 016 — 006 086 176 196 
Spring 078 | 219 378 
Summer 116 | 307 446 
Autumn 155 285 325 
Winter 107 157 163 
Winter Solstice 097 156 177 
Equinoxes 115 | 260 370 
Summer Solstice 135%). 35 438 
The Year 106 | 234 313 
DIURNAL VARIATION OF 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 maximum occurs about 6 p.m., Makerstoun mean time. 
A minimum occurs about 115 10™ am, cecisecccecceceeeeees Abo 
A secondary maximum occurs about 74 10™ A.M, ............005 Bac oae 
A minimum occurs between 9" p.m. and 5” A.M.,......c002.ce0ecessseees 
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 5" p.m. 
in some of the months about the equinoxes. The secondary maximum occurs at the same hour, 7" 10™ a.m., 
throughout the year. In the winter months, the principal minimum occurs between 9" 10™ p.m., and 5» 10™ 
am. The minimum near noon occurs about 94 40™ a.m. in mid-winter, and about 115 10™ a.m. in mid-summer, 
The following table has been formed in order to obtain, if possible, the period of the earliest mmimum. 
TABLE XXVI.—Diurnal Variations of the Total Force of the Earth’s Magnetism, deduced from 
Tables XII. and XIX. 
ott. ji Fp Summer Gott. Winter : Summer 
ies Abate Equinoxes.| cvistice. | Mean. |! Mm. | Solstice. |Eauimoxes.| soistice, | Mean. 
H. 0-000 0-000 0-000 0-000, H. 0-000 0-000 0-000 0000 
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 0 102 378 104 186 
13 000 010 049 O11 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 5 475 
