ExTEEME Positions. 



257 



TABLE XXXI. — Means of the Quantities in the three preceding Tables for periods of Three Months, 

 and for the Year 1843, with the Mean Positive and Negative Excesses of the Excursions of the 

 Magnets. 



m 



a 

 o 



> 



u 



.0 

 



Period. 



West Declination. 



Bifilar 



Magnetometer. 



Balance Magnetometer. 



Ranges. 



Above 

 Mean. 



Below 

 Mean. 



Excess. 



Above 

 Mean. 



Below 



Mean. 



Excess. 



Above 

 Mean. 



Below 



Mean. 



Excess. 



Declina- 

 tion. 



Hor. 



Comp. 



Ver. 

 Comp. 







/ 



' 



/ 



Sc. Div. 



Sc. DiT. 



Sc 



Div. 



Mic. Div. 



Mic. Div. 



Mic. Div. 



' 



X = l. 



Y = 1. 



( 



Spring 



12-54 



21-67 



- 9-13 



24-4 



36-0 



- 



11-6 



253-7 



68-5 



+ 185-2 



41-90 



0-00669 



000319 





Summer 



5-91 



17-08 



-11-17 



42-6 



43-9 



- 



1-3 



126-5 



117-5 



+ 9-0 



31-97 



0-01057 



000230 



ft 



Autumn 



7-80 



11-84 



- 4-04 



260 



20-7 



+ 



5-3 



86-1 



87-7 



- 1-6 



25-38 



0-00623 



0-00183 



Winter 



5-16 



6-69 



- 1-53 



11-8 



13-9 



- 



2-1 



70-7 



37-0 



+ 33-7 



16-24 



0-00329 



000118 



\ 



The Year 



7.86 



14-32 



- 6-46 



26-2 



28-6 



- 



2-4 



134-2 



77-6 



+ 56-6 



28-87 



0-00669 



000212 



/ 



Spring 



6-23 



7-39 



- 1-16 



12-7 



17-4 



- 



4-7 



101 



62-9 



- 52-8 



18-25 



0-00376 



0-00089 





Summer 

 Autumn 



-0-25 

 5-99 



9-12 

 9-77 



- 9-37 



- 3-78 



7-7 

 13-2 



6-2 

 3-8 



+ 

 + 



1-5 



9-4 



5-7 

 15-9 



37-5 

 98-1 



- 31-8 



- 82-2 



16-71 

 20-99 



0-00323 

 0-00356 



0-00048 

 0-00122 



u 



Winter 



2-53 



4-43 



- 1-90 



11-9 



2-8 



+ 



9-1 



6-9 



14-5 



- 7-6 



10-28 



0-00163 



0-00028 



\ 



The Year 



3-98 



7-55 



- 3-57 



11-4 



7-5 



+ 



3-9 



9-6 



53-2 



- 43-6 



16-55 



0-00304 



0-00072 



1 



Spring 



6-31 



13-50 



- 7-19 



23-7 



25-4 



- 



1-7 



79-2 



52-4 



+ 26-8 



21-29 



0-00529 



0-00143 





Summer 



7-09 



16-22 



-11-13 



23-7 



60-9 



~ 



37-2 



72-7 



97-4 



- 24-7 



24-94 



0-00728 



0-00158 



i 



Autumn 



8-01 



7-60 



+ 0-41 



21-2 



15-3 



+ 



5.9 



38-4 



48-8 



- 10-4 



17-49 



0-00436 



0-00089 



w 



Winter 



4-53 



11-00 



- 6-47 



6-6 



18-8 



- 



11-2 



40-9 



8-5 



+ 32-4 



16-34 



0-00273 



0-00060 





The Year 



6-52 



12-41 



- 5-88 



20-2 



29-5 



- 



9-3 



63-7 



53-6 



+ 101 



20-40 



000507 



0-00121 



The foregoing Table has been formed from the three preceding it by taking the means of the excesses or 

 defects, and ranges, for periods of three months. 



The extremes, given in Tables XXVIII. and XXIX., are evidently imperfect, as the obsei'vations include 

 only a limited portion of the 24 hours ; the conclusions to be drawn from the previous Table must, therefore, 

 be very restricted. 



From all the observations, the excursions of the declination-needle towards the east are shewn to exceed 

 those towards the west ; they all agree also in making this excess greatest in Summer. 



The results of the horizontal component differ in the three kinds of observations ; on the whole, the devia- 

 tions from the mean seem to be more negative than positive. 



For the vertical component, it has already been shewn that no result for ranges can be trusted that does 

 not include observations between midnight and sunrise. The term-day observations which include the 24 hours 

 give the excess negative ; and although the number of days from which this result is obtained are few, yet it is 

 true for 9 out of the 12 term-days, and for the remaining 3 the positive excess is very trifling. 



MAG, AND MET. OBS. 1843. 



3t 



