the intensity of magnetic forces , &c. 
39 
'Table IV. continued. 
<p 
82° 
OO 
0 
84° 
0 
, 
00 
1 
1 
/ 
A (p 
Dif. 
A p 
Dif. 
A p 
Dif. 
A p 
Dif. 
oo 
03 
06 
09 
12 
15 
18 
21 
*4 
27 
30 
33 
36 
39 
42 
45 
48 
5 * 
54 
57 
60 
38.936 
39*153 
•373 
•595 
.820 
40.047 
• 277 
.510 
•745 
•983 
41 .224 
. 468 
•715 
• 965 
42.218 
•474 
•734 
•997 
43-263 
• 532 
.805 
.217 
.220 
.222 
.225 
. 227 
.230 
•233 
•235 
.238 
.241 
•244 
•247 
. 250 
•253 
.256 
. 260 
• 263 
. 266 
.269 
•273 
/ 
43*805 
44.081 
. 361 
.644 
•931 
45.222 
.516 
.815 
46.117 
•423 
•733 
47-047 
.366 
.688 
48.016 
•347 
.683 
49.024 
•369 
.720 
50-075 
.276 
.280 
. 283 
.287 
.291 
• 294 
•299 
.302 
.306 
.310 
•314 
•319 
.322 
•327 
•332 
•336 
•341 
•345 
•351 
•355 
50.075 
•435 
.801 
51-171 
•547 
.928 
52.315 
• 707 
53-105 
.508 
.918 
54*334 
• 756 
55.184 
.619 
56.060 
.508 
•963 
57*425 
• 894 
58*371 
. 360 
.366 
•370 
•376 
. 381 
•387 
•392 
•398 
•403 
.410 
.416 
.422 
.428 
•435 
• 441 
• 448 
•455 
.462 
• 469 
•477 
58.371 
•855 
59*347 
.847 
60.355 
.871 
61.395 
.928 
62.469 
63.020 
•579 
64. 148 
.726 
65-313 
.911 
66.518 
67.136 
•765 
68.404 
69*055 
69.717 
•484 
.492 
.500 
.508 
.516 
•524 
.533 
•541 
•551 
•559 
•569 
•578 
.587 
.598 
.607 
.618 
.629 
•639 
.651 
.662 
I now proceed to the observations for the correction of which 
these tables were calculated. My principal object in making 
these observations, was to ascertain how far they would ena- 
ble me to determine the diurnal changes in the terrestrial 
magnetic intensity, and whether a series of such observations 
would not afford very accurate measures of such changes ; 
and I have before stated that I made them both within-doors 
and in the open air, in order to ascertain whether I had, in 
my former paper, assigned the true cause of the apparent 
anomalies which were noticed by Mr. Barlow and myself in 
these different situations. 
The first observations were made in-doors, in the same 
