NATURAL HISTORY. 
To estimate with certainty the variations, if any, of this climate, long continued and care- 
full)' conducted observations would be necessary. In defect of such it may be mentioned that the 
farmers believe, and assert, that a marked amelioration has taken place—the times of seeding 
and harvest being both considerably advanced. In support of this opinion may be adduced the 
extending and successful cultivation of wheat, and the increased number of quails, a bird now 
comparatively abundant. However, though the circumstance of a recent improvement in this 
respect may be probable, it would be rash to pronounce it, on the present evidence, permanent. 
In the Annals of Derry, by Mr. Gillespie, two remarkable frosts are recorded. The first 
was in 1740, when the river was frozen over, and an ox roasted on the ice, opposite to the 
Ship Quay. The other was in 1814, when the ice on the river was so strong that carriages 
were driven over it in several places, and—on the 6th of February—a part of the bridge 
was carried away by masses of ice, floated down the river by the ebb tides and a very 
high wind. And, when it is recollected that such unusual and impressive events are more 
likely to dwell on the memory than the more simple and unobtrusive fact of a peculiarly mild 
and genial season, it may be reasonably doubted whether the change alluded to is more than a 
periodical return of warm seasons alternating with those of severe and rigorous cold. 
There are similar instances of hard frost, and other variations of weather, recorded in the 
earlier annals of the district, which, however, are not so immediately connected with the parish 
as to claim notice here. The most remarkable circumstance bearing on the subject was a meteoric 
appearance, which accompanied the death of bishop Murry O’Coffy, in 1173. [See Local 
History.'] 
NATURAL HISTORY. 
Geology. —A geological description, founded on the principles of practical utility, naturally 
divides itself into two sections :—1st Rocks (including clays, sands, &c.), as regards their mutual 
relations in geological science; 2nd Rocks, &c., as regards their application to practical 
purposes. 
And the first of these sections may again be divided into two sub-sections, namely 
1st. Rocks in situ (including stratified clays and sands)—Being a consideration of the 
order of their geological position, and of the accidents which have affected or modified their 
arrangement. 
2nd. Detritus —Being a consideration of those accumulated fragments, which now form 
beds of clay, sand, or gravel, and have proceeded from the disintegration, removal, and re¬ 
arrangement of those pre-existing rocks, which are now recognized as part of the visible crust 
of the Earth. 
Section 1. — Sub-section L — Rocks, 8fC., in situ. 
The geological structure of the parish is simple, and it may be observed that it has no exact 
geological boundary—the same rocks occurring on the opposite side of the Foyle, and on the W. 
and N. of the parish, in the county of Donegal. The great mass of the primary schistose 
rocks, which occupies so much of the western part of the county, spreads over its whole surface, 
with the exception of a considerable detritic patch at Culmore, in the N. E. of the parish, which 
probably conceals a part of the new red sandstone—that rock being visible at the extreme 
northern end of the parish,—and of several very limited deposits of mud and clay, which on 
the S. E. skirt the river Foyle. Within this space the rocks exhibit a considerable variety of 
texture, passing through several steps of progression from a rough and knotty pseudo-gneiss 
into a smooth, even, and apparently homogeneous slate. That these varieties have a definite and 
regular order of arrangement is improbable, although it does appear that some of them recur 
frequently with the same characters, and are sufficiently persistent over a large extent of country 
to be admitted as types of the following subdivisions :— 
1st. Mica slate, passing into gneiss. G. m. 
2nd. Mica slate, passing into clay slate. G. m. c. 
3rd. Mica slate, passing into quartz slate. G. m. q. 
The dip varies in direction from N. to N. W., and in amount from 30° to 55°; but here, 
as in all the primary slates, much doubt and difficulty must attend the determination of the dip, 
and the very fact of distinct stratification is sometimes questionable. The lamina of these 
b 2 
