Dips, observed by Capt. P. P. King, 1826 to 1831.
Station.Needle.Marked end a N. Pole.Marked end a S. Pole.Dip deduced.Remarks.
aa′a″a″′
° ′ ° ′ ° ′ ° ′ ° ′ ° ′
Rio de Janeiro115 58,513 02,415 05,713 18,014 16,214 00,1 S.
214 39,412 30,414 49,013 07,313 44,1
Sta. Catharina122 54,124 04,721 55,622 46,022 49,622 12,4 S.
223 22,820 32,323 34,221 00,722 03,6
321 17,821 08,523 26,222 57,221 44,0
Monte Video136 48,437 49,335 25,437 26,937 00,736 28,4 S.
237 17,234 53,837 17,134 37,435 59,3
336 36,135 10,337 12,436 13,236 25,3
Port Famine164 41,752 42,665 51,254 54,059 44,959 52,6 S.
260 41,959 32,260 32,159 33,660 04,5
360 03,958 43,460 35,559 37,559 48,5
Gorriti141 09,930 50,941 04,631 32,635 38,335 05,9 S.
236 29,233 26,435 17,134 02,734 43,8
334 52,334 18,536 06,935 01,334 55,6
Sea Bear Bay158 26,547 53,860 34,847 53,453 13,553 13,5 S.
St. Martin Cove165 24,754 23,865 47,754 43,659 46,459 43,8 S.
260 25,659 28,359 49,958 48,659 38,4
359 48,958 40,760 43,459 53,359 46,6
Chilóe154 23,945 38,356 19,245 11,149 59,449 52,6 S.
250 24,049 12,950 28,448 29,649 38,7
349 43,948 48,351 24,550 02,249 59,7
Valparaiso143 04,533 59,944 38,834 54,638 40,140 10,7 S.
240 48,240 49,740 53,741 09,740 55,4
340 54,940 45,440 49,841 16,740 56,7
Juan Fernandez150 22,739 16,051 08,240 03,244 40,553 13,5 S.
244 19,345 57,643 45,846 13,745 04,6
345 50,445 07,944 34,843 25,744 44,7
Talcahuano45 10,0 S.** The particulars of this
observation are wanting.

The following Table contains Captain King's Observations of Intensity, with the times of vibration corrected for the arc and reduced to a standard temperature of 60°.

Magnetic Intensity, observed by Capt. P. P. King between 1826 and 1831.
Station.Date.Time.Therm.Corrected
Time.		Particular place.
s.°
Greenwich1826Mar.22734,4555,0733,97Observatory.
1831Jan.24775,8041,6776,01
Madeira1826May31628,6866,0627,79Consul's Garden.
Teneriffe—June12607,9675,0606,73Fort St. Pedro.
Port Praya— —22559,5381,5557,08Landing Place,
Quail Island.
— —24557,5885,0
Rio de Janeiro—Aug.29546,3677,0545,16Rat Island.
1827Sept.12552,0675,5
— —15552,9580,0551,70
— —15553,7383,0
— —15553,4885,0
1828Dec.21562,5584,0561,05
Sta Catharina1827Nov.3554,4267,5553,58Anhatomirim.
Gorriti1826Oct.29550,6863,0549,44The Well.
—Nov.6549,6366,0
1829Jan.10564,1280,0562,78
Monte Video1827Dec.18555,1278,3553,87South point near
the sea.
1828Oct.8562,0072,5560,95
1830June1565,4159,0564,89
Port Sta Elena1826Dec.4557,2668,0556,42Landing-place.
Sea Bear Bay1829Mar.20577,3670,0576,37Landing-place.
St. Martin Cove1827Jan.15584,8856,0584,29
— —15583,4858,0Head of the
Cove.
— —22585,8255,0
—Mar.27585,8264,0585,08
Port Famine1828Jan.28589,7555,0589,36Observatory.
—May8596,4943,8596,54
—June18595,8632,7595,81
—July30594,8536,2
1830Apr.30598,9545,0598,97
Chilóe1829Sept.1565,4054,0565,23San Carlos.
—Dec.15565,6953,0
Juan Fernandez1830Feb.19552,7770,0551,83Landing-place.
Talcahuano1829Dec.18556,4267,0555,59Fort Galvez.
1830May12557,1860,5557,18
Valparaiso1829Aug.4549,1059,0548,59Almendral.
1830Jan.11551,7777,0551,60
—Feb.1553,5068,5

At Rio de Janeiro, which was the first station observed at in South America, the cylinder was vibrated in August 1826, September 1827, and December 1828; in the intervals between these dates are comprised the greater part of the observations on the east side of South America. There is no direct observation at Rio subsequently to December 1828; but we are enabled to supply the time of vibration, which would have been observed had the cylinder been employed at Rio on June 1, 1830, in the following manner. We have seen that on the 15th September 1827 the time of vibration was observed at Rio; on the 18th December following it was observed at Monte Video. These observations give the intensity at Monte Video relatively to that at Rio, subject to whatever change of magnetism the cylinder may have undergone in the interval of three months. This comparison was repeated in the following year, on Captain King's return from Monte Video to Rio, the interval being nearly of the same duration, and the order of the experiment reversed, the passage being in this instance from Monte Video to Rio, it having been before from Rio to Monte Video. On the supposition of an uniform, or nearly uniform rate of change in the cylinder, the errors arising therefrom during the two passages would be of opposite kinds, and should compensate each other in a mean of the two comparisons. Calling the force at Rio unity, these comparisons give its value at Monte Video respectively as follows, namely,