84 
MR. A. W. RtiCKER AND DR. T. E. THORPE ON A MAGNETIC 
Mean Annual Decrease of Inclination in Scotland between 1857 and 1884-8. 
Station. 
Mean annual 
decrease. 
Station. 
Mean annual 
decrease. 
Lerwick. 
0-96 
Fort Augustus 
1-21 
Kirkwall. 
1-07 
Aberdeen. 
1-33 
Stromiiess. 
1-27 
Pitlochrie. 
1-40 
Thur.so. 
1T5 
Oban. 
1-27 
Wick. 
ITl 
Port Askaig , . , . 
1-38 
Loch Inver. 
I’32 
Locbgoilhead .... 
1T2 
Stornoway. 
0-90 
Edinburgh. 
1T4 
Callernish. 
0-99 
Glasgow . . 
1-42 
Golspie. 
1-38 
Berwick. 
1-33 
Banff. 
1-33 
C umbrae . ... 
0-94 
Elgin. 
1-30 
Campbelton . 
1-39 
Inverness. 
1-37 
Ayr. 
1-5G 
Kyle Akin. 
1T2 
Dumfries. 
1-45 
Dalwhinnie .... 
1-41 
Stranraer . 
1-54 
Using these figures and the numbers calculated as above described from Table II., 
p. 82, we get the mean annual decrease between 1857 and 1886 in different parts of 
the United Kingdom, as follows :— 
District. 
Mean annual decrease between 
1857-8 and 1884-7. 
N. of Scotland. 
1-20 
S. of Scotland. 
1-36 
N. of England and N. Wales 
1-57 
Midlands and Wales. 
1-71 
S. of England. 
1-84 
N. of Ireland. 
1-68 
S. of Ireland. 
1-90 
Althoi’.gh we give these numbers as showing the mean results for districts of con¬ 
siderable size, the figures obtained at the individual stations appear worthy of caneful 
study. 
The observed,values of the annual decrease for 1857-87 for Scotland, and those 
calculated for the same period for England and Ireland from the 1837-87 surveys 
are inserted in the accompanying map (fig. 1). 
The general increase from east to west is evident, but in Great Britain there are 
some stations the annual decrease at which is less than at those which are nearest to 
them on the eastern side. 
To test wdiether the differences were accidental a number of supplementary stations 
w'ere taken on the Wye. 
At Malvern and Brecon the calculated secular rates between 1857 and 1886 are 
— 1'‘94 and — 1'‘87, and at Clifton and Cardiff — i'‘87 and — 1'‘85. In each case 
