SURVEY OF THE BRITISH ISLES FOR THE EPOCH JANUARY I, 1891. 033 
Ireland. 
District 18. — Antrim. 
The large masses of basalt which exist in Antrim make it very difficult to obtain 
evidence of regional disturbance. 
The plan we adopted was as follows On the eastern coast there are places where 
non-magnetic rocks occur. On these a number of observations were made, which 
establish an agreement between the ridge and valley lines of Antrim and those on 
the opposite Scotch coast. 
We have already seen that a well-marked valley line extends through Galloway to 
Portpatrick. A straight line drawn from Glencaird in this valley to Loch Ranza in 
Airan is a little longer, but almost parallel to a line drawn from Bangor (just opposite 
Portpatrick) to Ballycastle (Antrim). 
The following alternations of Vertical Disturbance (expressed in terms of 0-00001 
C.G.S. unit) occur at stations or groups of stations on or close to these lines :— 
Scotland. 
Ireland. 
Valle_y. 
Glencaird .... — 91 
/ Bangor.—90 
1 Carrickfeig'u.s . . . — 4d 
Ridge .... 
Penwherry . . . . -j-187 
Larne.+21 
Valley. 
Gil'van.-—104 
Ballygalley Ba^' ... — 2 
Ridge . 
Brodick.+223 
(Carnloiigh . . . . +33 
< Waterfoot . . . . +17 
[ Torr Head ... +61 
Valley. 
Loch Ranza.... — 29 
Ballycastle (Antrim) . + 8 
Although, therefore, the alternations in Ireland are much less violent, they corre¬ 
spond to those on the opposite coast, and when the valley and ridge lines are drawn 
on both sides of the North Channel their connection is still more evident. 
In the interior of Antrim spots were selected for the stations where the surface 
soil at all events was non-magnetic. For this purpose the observers carried geological 
maps, which had been studied, and on which, in some cases, the apjiroximate position 
of the stations had been chosen before they started on their summer tour. Thus, at 
Templepatrick, a patch of chalk occurs in the midst of the basalt. The observations 
were made on this. At other places nothing better could be done than to pick out 
MDCCCXCVI.—A. 4 
