ON THE MAGNETIC INTENSITY OF THE EARTH. 15 
Kupffer, as having occurred in his experience, and I have my- 
self met with an instance of the same kind. M. Lenz has em- . 
ployed no correction for this needle; and the vibrations of the 
vertical needle appear also to have been uncorrected for tem- 
perature. 
The harbour of St. Peter and St. Paul is the fundamental 
station of Capt. Liitke’s determinations. ‘The value of the in- 
tensity there, 1-447 to 1°348 at Paris, is stated by M. Lenz to 
be taken on the authority of M. Hansteen. 
Capt. Liitke used both his dip and intensity needles at sea in 
favourable weather, placing the instruments on a board sus- 
pended in gimbals above the companion. His sea observations 
appear to be viewed by M. Lenz as not entitled to equal weight 
with those at the land stations, but as valuable additions. Of. 
51 intensity results, 16 are at land stations, and are entered in 
the general table; and I subjoin, as in the case of M. de Hum- 
boldt’s, a separate table of the 35 results obtained at sea. 
Lat. Long. Date. Intensity. Lat. Long. Date. Intensity. 
Souru. 1827. NorTH. 1827. 
/ 
29 10 | 313 35 |16 Jan. | (a) 0-924*|| 0 35 | 232 56 | 8 May | (2) 1.013 
40 55 | 307 0 |25Jan. | (a)1-110 || 2 24 | 232 08 | 9 May | (0) 1-019* 
49 18 | 302 48 |31 Jan. | (a) 1:268 || 13 13 | 227 0/19 May | (8) 1-112* 
53 16 | 301 37| 3 Feb. | (6) 1:320*|| 23 26 | 218 02 | 25 May | (6) 1-212* 
55 25 | 298 27| 8 Feb. | (b) 1:413 || 25 21 | 213 56 | 30 May | (2) 1:376* 
4100 | 282 30 | 1 March] (6) 1:324 || 40 28 | 213 35] 1 June | (0) 1-456 
29 38 | 278 26 |11 April | (c) 1°153*|| 44 54 | 214 50| 3 June | (d) 1:573* 
21 51 | 268 05 |18 April | (c) 1°046*|| 48 44 | 216 37| 6 June | (d) 1-653 
13 09 | 251 20 |27 April | (c) 1:014 |] 52 29 | 219 08.| 9 June | (b) 1-662* 
9 38 | 243 25 |30 April | (c) 1°141*|| 45 27 | 159 02 | 23 Oct. | (b) 1-303 
6 01 | 240 08 | 2 May | (4) 1:005*|| 39 07 | 159 03 | 26 Oct. | (4) 1-186 
420 | 238 13 | 3 May | () 0-998 || 32 59 | 161 49| 1 Nov. | (d) 1-113* 
229 | 236 26 | 4 May | (a) 1:000*|| 18 44 | 163 55 | 13 Nov. | (8) 0-989 
202 | 236 04| 4 May | (»)0-996*|| 11 27 | 161 52 |18 Nov. | (5) 0-970 
115 | 225 30] 5 May | (c)0-989*|| 417 | 162 54 |23 Dec. | (a) 1-001 
110 | 234 31 | 6 May | (8) 0-995*|| 347 | 162 59 |23 Dec. | (a) 1-010 
0 56 | 233 17 | 7 May | (c) 0:990*| 2 56 | 162 50 |24 Dec. | (a) 1-018 
> 
on 
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(a) 0 990 
__ The results with an asterisk are so marked in M. Lenz’s memoir to signify 
observations made under less favourable circumstances than the others. The 
sixteen which are not so marked are entered in the general table. 
(a) designates results obtained by means of the horizontal needles; (6) those 
b > ia of the dipping-needle ; and (c) results which are a mean of both me- 
thods. 
King, 1826-1830.—These observations were made during 
