Le A, Bouer— 
Variation of Terrestrial Magnetism. 
111 
used critically. The following novel results will afford strik- 
ing evidence of this. 
I shall not give here the original data, as it is my intention 
some day to publish the total material together. 
ean be understood without the original figures. 
Table I is intended to exhibit mainly the “distribution” 
phenomena, Table II those of the “secular variation.” 
The results 
TasBlLE I. Distribution. 
horizon. 
horizon. 
Minus: 
DECLINATION. 
Mean for Latitude. Range for Latitude. 
Date |+60 +40 +20 0 —20 —40 —60 | Mean |+60 +40 +20 0 —20 —40—60) Mean 
| 
° ° ° ° ° ° ° ° ° ° ° ° ° | ° 
meso? 2 il +05 05 +11 +273 +2°8) +1°5 |70°8 35°T 28:3 ane 33:9 46" "q 66°8) 44:5 
teo0 E20 OT +-0°3 £05 IS +277 +124) +1°3 172°3 42°9 33°0 31°6 37°3 48°7 T1°3| 48°9 
fea oO +17) +02 +02 +14 +370 +21) +16 |96°0 41°0 30°2 31-7 37°3 44-3 73° 5 49°1 
1858 +3°7 +1:0 +0°3 +0°7 +1°6 +3°2 +2°4) +1°8 |91°3 43°4 30°5 31°7 39°3 49°4 74:8) 51°5 
1872 |}4+3°1 +0°'7 +0°2 +0°8 +2°0 +3°3 +3°2) +1°9 (86:2 44:0 30°3 aa 8 38°8 50:2 74:3) 50°4 
—1880 |+2°0 +0°8 +0°4 +0°9 +1°3 +3°4 +3°5 +1°8 |84°2 43°9 29°7 29°6 39°9 509 75°6 50°5 
«1885 }+2°5 +077 +04 +1°0 +1°8 +3°5 44:1) 4+2°0 186°8 43:0 29°1 29°7 39°1 51°1 78°3) 51-0 
Mean} +2°6 +0°9 +0°3 +0°7 +1°6 +3°2 + 2°8 +1:7 |82°5 42°0 30°2 30°3 37:9 48:8 13:5) 49°3 
| 
INCLINATION. 
Mean for Latitude. Range for Latitude. 
oie 205 0 20 —40 —60 |Mean|+60+40+20 0 —20 —40 —60| Mean 
° ° ° ° ° ° o ¥* ° ° ° ° ) ° ° ° 
+74°9 +588 +33°2 —1'9 —34°0 —59'1 [—70°8] + 0°2 |13°2 21°4 39°5 47°8 38°8 26:3 [22-0] 29'9 
75-4) 260°. 34-6 —1°8 —35:9 —57-7 —70°8 |+0°6 |14°3 21-5 37-4 55:2 47-1 30°71 23°6 | 32-7 
+75°3 +59°0 +342 —2°2 —36':0 —57°2 —70°9 | +0°3 |15°3 22°5 33:8 53:0 45°5 33°0 28°0 | 33:0 
ia +1602 4-30°2 —2°1-—36°] —57:2 -—70°5 |+0°7 |15'6 23:0 35°5 50°5 49°5 34°09 27°0 | 33°7 
7a 4 +596 +35°0 —2*1-—3673 —57:°2 —70°6 |+0°5 |15°0 20°2 33°6 48°4 46°8 34°0 27-2 | 32:2 
e753 099 3475 —3*)—36°8 —57'6- —70°6: | +-0°2 |15°4 20:2 32°8 50-2 46°3 36°3 28:0 | 32°7 
ea -e O-7 343 — 3-2 —36°8 —dbT-2) —70:°2 |+0°4 114-7 19:6 31-7 49°6 47:0 36°2 29°0 | 32°5 
ae +596 +344 —2°3 —36:0 —57°6 —70°6 |+0°4 14°8 21°2 34°9 50°7 45°9 32°9 26°4 | 32-4 
* Supplied temporarily from value for 1830. 
Meaning of Signs.—Plus: North Latitude, West Declination or Dip of north end of needle below the 
South Latitude, East Declination or Dip of north end of needle above the 
