THE BERMUDA ISLANDS. 22 
Proofs of subsidence are reported to exist in the occur- 
rence of shoreward dips of the sand-rock into and below the 
water-level (Rice); in the existence of caverns submerged 
over fifty feet, with stalagmites rismg from their floors, now 
far beneath the surface (Heilprin); and the fact mentioned 
in the Report of the Challenger Expedition, that a peat-bed, 
stumps of cedar, land snails (//elic LBermudensis), and loose 
masses of the drift-sand rock were found on Ireland Island at 
a depth below tide-level of forty feet, in the excavation for 
a floating dock. When these cedars were growing, the land 
was consequently forty-five feet or more above its present 
level. It is probable that at this time there was a long 
period of rest or cessation in the subsidence, and that during 
it the drift-sand formation of the island, including that of 
“North Rock,” was chiefly made. Afterward, when the sub- 
sidence was resumed, the work of degradation began. 
A comparatively recent elevation is indicated, according 
to Professor Rice, by the height of the beach-sand rock. fif- 
teen feet, on part of the north side of the strip of dry land. 
The origin of the “red earth” ' making much of the soil 
1 Analysis of the coral sand of Bermuda, and mean of three analyses of the 
red earth, by Mr. F. A. Manning (Agricultural Report, at Bermuda in 1873, of 
Maj.-Gen. J. H. Lefroy). 

1. Coral sand 2. Red earth. 
Warhbonicaciduer erm aces oe eS 4.06 
Ae ae gen eth tas Sich os rte oh ee OTT 5.95 
Wapnegiaie vers War Gar ist acc eeu 52a 1 109 0.36 
OLAS Estee testes cleat a ciate ae 2 BOLOG 0.14 
SIQCAMMMEE ah A Seicsccist uss. waa) esl OLD4: 0.03 
Alumina ‘ Cpe aera esate ¢ 16.94 
Tron sesquioxide ( 19.58 
SAUBNUME ACTON a 5a ees) Yee e 9 OL20 0.05 
Chlorinehysesy city ease e el ee eane ty OL02 0.015 
PhOSspHOLiclacid someway ee O08 0.70 
Sauls stt aerrpie es stele ee sre 1 OL05 56.60 
Oreanic substance’. 2) .) 2) 2) S180 15.41 
102.00 99.81 
Excluding the 15:41 per cent of organic substance in the red earth, 100 parts, 
according to the above, contain about 23 per cent of iron oxide, 20 of alumina, and 
43 of sand, besides some lime carbonate and small portions of the other ingredients 
enumerated, 
15 
