TRANSACTIONS OF SECTION A. 419 
a positive departure=124 and a negative =89, representing a range between 
extreme values of 213 for a mean value of 1,000. Again, in the second inequality 
we have a positive departure=131 and a negative=104, representing a range 
between extreme values of 235 for a mean value of 1,000. In both cases, therefore, 
the range of oscillation is between one-fourth and one-fifth of the mean value. 
TABLE oF SurroseD SuN-spot INEQUALITIES OF SHortT PERIOD. 
Period=26-089 Days Period=26°255 Days 
1852-43 / 1844-55 | 1856-67 | Whole 1832-43 1844-55 | 1856-67 Whole 
+ 159 }|— 224 !)— 66|}— 131} — 535 | — 1,037 |— 775 |.— 2,347 
— 380|— 286 ;— 390 | — 1,056] — 1,131 | — 1,417 |— 782 | — 8,330 
— 416)— 628 )— 351 | — 1,375 | — 1,031 — 1,345 |— 994 | — 3,370 
— 452|}— 405/—. 380|— 1,237} — 1,618.) — 832 |— 882) — 3,332 
+ 32);— 884}— 608 |— 1,460} — 1,283 | — 819 | —1,146 | — 3,248 
— 181}— 740}— 616 | — 1,537 | — 1,383 | — 1,151 | —1,224 | — 3,758 
— 723 |— 496)— 482 )— 1,701] — 1,231 | —, 642 | —1,424 | — 3,297 
Sze |— Ofd.)—. (dd) — 168k) — 683) —.). G17 | — 522 | — 1822 
— 399 |— 675 |} — 1,361 | — 2,435 | — 1,101 — 1,045 |— 412] — 2,558 
—1,306 |— 475 |— 1,214 | — 2,995 | — 1,445 | — 834 |— 350] — 2629 
—1,250 | — 553 | — 1,421 | — 3,224] — 573 | — 174. |}— 252.) — 999 
— 808 |}— 225 '|— 1,201 | — 2,234] + 244 “EOE” ea Seo 
— 706|/— 194 ])— 883 | — 1,783 | + ll | + 271 |+ 198] + 480 
Saeaa 2 eet 2B EM SOG TOs) ee LO8h yb) 259 a> 16 EPO eT 
ia 4}+ 1/— 667);— 662] + 573 | + 933 |} + 316} + 1,822 
— 35 )+ 220) + 51) + 236) + 1,490 | + 823 | +1,124 | + 3,437 
+ 527/+ 407}+ 316) + 1,250] + 1,653 | + 1,490 | +1,597 | + 4,740 
+ 304] + 583 ]}+ 272 | + 1,159] + 1,381 + 1,653 | +1,791 | + 4,825 
+1,310 |} +1,128 |} + 800 | + 3,238 | + 1,459 | + 1,613 | +1,723 | + 4,795 
41,511 | +1,600 | + 1,335 | + 4,446] + 1,442 | + 1,308 | +1,132'| + 3,882 
+ 567/|+1,110| + 1,319 + 2,996] + 1,242 | + 919 |+ 560 | + 2721 
+ 493 | +1,026 | + 1,418 | + 2,937] + .710 | +. 885 |) + 413] + 2,008 
+1,232 | + 424 | + 1,977 | + 3,633 | + 535 | + 572 |+ 290] + 1,397 
+ 584 /— 110/ + 1,985 | + 2,409] + 722.) + 501+ 178) +~° 950 
+ 318 | + 172) + 1,633 | + 21237 + 408 = p05) — 26) | = ) 229 
faeeton — Te) SCOR 102 1 16)— 891 |}— 80] — 955 
47,256 | +6,682 | +11,657 | + 25,129 | +12,014 | +11,180 | +9,322 | 431,874 
—7,256 | —6,682 | —11,657 | — 25,129 | —12,014 | -11,180 | —9,322 | —31,874 
The first number in each case represents the phase corresponding to January 1, 
1832. 
6. On the Forms of the Influence exerted by the Sun on the Magnetism of 
the Hurth. By Professor Batrour Stewart, F.R.S. 
The object of the present paper is not so much to offer an hypothesis on the 
physical nature of the sun’s influence on the magnetism of the earth, as to present 
the various facts already known regarding this influence in a systematic form. If 
in doing so an hypothesis of solar action shall be brought forward, it must be 
regarded simply in the light of a working hypothesis, which may prove serviceable 
as a thread on which to string the facts. 
One way in which the sun influences the magnetism of the earth is in producing 
the well-known daily variation. Of this the variation of magnetic declination is 
the element which is best known, and the chief peculiarities of this may be 
described in a very few words, In the northern hemisphere the north end of a 
ED 2 
