364 On the reialive Heights of the Levels 
commence ; stretching for many miles to the eastward, where 
your ladyship admired some of them so much. 
“© On the southern part of this boundary*, westward of Lough 
Neagh, granite seems to preponderate, and I have found red 
granite in abundance in the parish of Kildress; but when we 
enter Derry, the area for a great way to the westward is schistus, 
mixed with numerous quarries of stratified sandstone,’ and pri- 
mitive limestone, blue, crystallized and wvnstratified. 
“© Had your ladyship+ kept by the eastern boundary of the ba- 
saltie area, it would have led you, as the area inc reased in width, 
to Magheralint, where you w ‘ould have encountered a new va- 
riety of limestone, quite different from all I have mentioned, and 
particularly that near it at Kilmore 5 the latter a brownish red, 
free from flints, while the Magheralin and Moira limestone, and 
all the strata northward, are pure white and full of flints. 
‘“‘ The country or stripe to the eastward of the basaltic and 
limestone line, seems mostly indurated clay§, with quarries of 
stratified sandstone through it; and some gypsum quarries, as far 
as Cansielitexgus, and all crossed by many whin dykes. 
‘ This detail must be very tedious to your ladyship, but J 
wish to give you every opportunity of verifying my statement, 
whenever you may happen to approach, or pass through any of 
the separate systems I mention; it is upon their numbers and 
distinctness from each other, that I deny the trace of any great 
s paenenal operation on the surface of our globe so as te disturb 
; but the observations which these facts give rise to, and the 
ioe to be drawn from them,’ must be reserved for another 
letter. 
“ T remain, with great respect, 
* Your ladyship’s very humble servant, 
<* W. Ricnarpson, D.D.” 
LXXIII. On the relative Fish of the Levels of the Black 
Sea and Caspian Sea. By Messrs. MaurtcE ENGELHARDT 
and Francis Parror ||. 
Ore of the chief objects of the travels of Messrs. Engelhardt 
and Parrot to Caucasus and to the Crimea, was to determine 
* This sentence I cannot clearly coniprehend: Does it mean, that in 
Tyrone County, near to Lough Neagh, Granite abounds?. My Map does 
not show Kildress; Where is it?. J. F. 
+ On leaving Gosford Castle. J. F. ¢ Isthis Maherlin, in Down 
County? Ph. M. xxxix. p. 277 :and where is it situated?. J. F. 
§ Query Red Marl? Ph. M. xxxix. p. 272.—J. F. 
{| Extracted from a Voyage to the Crimea and Mount Gaucasus.— 
( Reise in die Krym und den Kaukasus.) Berlin 1815. 2 vols.—dAnnales dé 
Chimie et de Physique, tome i. Jan. 1816, p. 55. 
by 
