MAGNETICAL OBSERVATIONS IN SCOTLAND. 



113 



Table V. (continued.) 



Melrose 



Helensburgh 



Loch Ranza 



Campbelton, 

 Stranraer..., 



Bangor .... 

 Dublin 



Sept. 



6 



7, 

 13 

 14, 

 14. 

 16. 

 16. 

 17. 

 18. 

 18. 

 Sept. 21. 

 Oct. 3. 



3. 



3. 



4. 



6 40 p, 



8 45 a, 

 2 10 p, 



11 45 A, 



12 05 p, 



9 30 a. 

 9 50 a, 



7 20 a. 



2 40 p. 



3 10 p. 

 11 10 a. 



9 25 A. 

 9 45 A. 

 2 55 p. 

 I 15 p. 



Time of 

 Vibra- 

 tion. 



.M. 295-68 



.M.1296-55 

 ,M.'301-61 

 ,M.'300-99 

 ,M.'301-23 

 •M. 302-76 

 .M.'303-39 

 .M.'298-30 

 M.'297-03 

 M.1296-42 

 ,M.'295-2S 

 M.'291-02 

 M.'291-24 

 M. 291-37 

 M.291-73 



46-5 

 53-5 

 61-5 

 57-0 

 59-0 

 58-0 

 60-0 

 50-0 

 56-4 

 54-4 

 49-6 

 44-5 

 44-5 

 49-6 

 53-5 



Corrected 

 Time. 



Place of Observation. 



|- 296-85 

 !■ 301-33 



► 303-15 

 299-05 



■297-06 

 296-04 



292-21 



FieldE. of the Abbey. 



Field E. of the town. 



Sea-beach. 

 Sea-beach ; on red sandstone 

 Field S. of the town. 

 Grounds of the Castle. 



r Provost's garden, Tri- 

 L nity College. 



From the near agreement in the respective times of vibration 

 of the cylinders in Dublin in July and in October, we may infer 

 that the magnetic state of each cylinder had experienced little, 

 if any, alteration in the interval; an inference which is also 

 confirmed for a portion of the interval by the correspondence in 

 the times of vibration at Helensburgh in July and September. 

 The times of vibration in Dublin at the two periods referred to 

 are as follows, viz. 



Cyl.L(a). 



Cyl.L(i). 



July 24 and 25 243-47 292'96 



October 3 and 4 243*92 292-21 



Whence it would appear, if we ought to draw any conclusion 

 from such small differences, that Cyl. L. (a) had sustained a 

 small decrease of magnetism in the interval, and Cyl. L (Z»), on 

 the contrary, a small increase, and very nearly to a proportionate 

 amount. However this may be, we cannot err materially in 

 regarding the mean of the times of vibration of each cylinder in 

 July and October, as its rate in Dublin comparable with the 

 rates observed at the different stations in Scotland. The fol- 

 lowing Table has been computed accordingly. The first of the 

 three columns under the general head of "Horizontal Intensity," 

 expresses the ratio of the horizontal force at each station to 

 imity in Dublin, deduced from the times of vibration of Cyl. 

 L (a) ; the next column the ratios deduced from Cyl. L (Z») ; 

 and the third column contains the ratios deduced from a mean 

 VOL. V. — 1836. I 



