SYMONDS — NOTES OF A GEOLOGIST IN IRELAND. 



381 



were mucTi interested, in travelling from Dundalk to ITewbliss, in ob- 

 serving the '^Escar-drift " of tlie Irish geologists, which rests in long 

 ranges of gravel-hills along the sides of the valleys. The underlying 

 rock consists of Silurian slates, and the overlying drift appears to have 

 been deposited by quiet eddies. 



The drifts of Ireland are divided by some geologists into ; — 1st. The 

 Clay Drift. 2nd. The Great Drift. 3rd. The Escar Drift. The last 

 is supposed to be the effect of eddies, as the land approached the 

 surface.^'' ITuch of Ireland has evidently been submerged long after 

 the Boulder-drift" epoch; and the rounded hills of the Escar-drift" 

 being, to a certain extent, stratified gravels, must have been deposited 

 by currents of water, and not by glaciers or floating bergs. 



As we travelled from Kewbliss to Enniskillcn, our attention was 

 directed to the remains of former lakes, which are now actually in the 

 transition state, and turning into red bogs, of which kind the greatest 

 portion of the bogs in Ireland consist. An able paper, by Mr. D. 

 Moore, *'0n the plants, which, by their growth and decomposition, 

 form the principal part of the Irish turf-bogs," read in section D, at 

 the British Association meeting, has enlightened us on a subject of 

 much difficulty. 



Mr. Moore divides the varieties of bog into red bog, brown bog, black 

 bog, and mountain-bog, and considers " the differences of colour and 

 consistences of matter, of which each variety is composed, to depend 

 chiefly on the localities where the substances are produced, according 

 as they vary in different degrees of moisture, temperature, and altitude, 

 whereby the growth and decomposition of vegetables are affected." 



Red bog and brown bog are the least valuable for fuel, and '''aro 

 supposed to have been formed on the sites of extensive ancient lakes or 

 very wet morasses, which may be inferred from the very small quantity 

 of wood mixed up." Sphagnums constituted a large portion of the 

 substance of the peat, and the roots and branches of phanerogamic 

 plants form a kind of framework, and bear up the cryptogamic 

 species. 



In the absence of all trustworthy experiments, " the rate of increase 

 could not well be determined ; but holes, out of which turf had been 

 cut, had been observed to be filled up with soft vegetable matter to the 



See paper, by W. Birmingham. Edin. New Pldl Journ., October, 1858, 

 page 326. 



