Section of Ferruginous Strata. 185 



former : it was several feet in length before broken ; the undulating, 

 circular annuli, are very peculiar. It is an inch and a half in diam- 

 eter, and two in length ; the center cavernous. No. 65, (page 15 

 of the wood cuts,) is evidently a fleshy root of some plant. The 

 figure is the natural size, deep transverse folds are placed at short 

 distances through the whole length. I have several similar ones. 

 The fossils from this bed are all perfect iron ore. The specific grav- 

 ity of this ore is 2.46. — 3 feet. 



6. Lime rock — oolitic, in thick beds, compact and solid, of rath- 

 er a dark carbonaceous color, containing particles of white calcare- 

 ous spar, and numerous species of imbedded shells of the families 

 Producta, Spirifer, Encrini, Stc. Figures of shells, Nos. 38, 39 

 and 40, (page 26 of the wood cuts,) are from this bed. Descrip- 

 tions given as above. This bed is eleven- feet in thickness and af- 

 fords a supply of calcareous material, used in fluxing the ores at the 

 adjacent furnaces. — '11 feet. 



7. Fine grained, argillaceous sandstone rock. The particles of sand, 

 fine and round, cemented by a fine clay with a little iron. The up- 

 per portion of the bed is light colored ; the lower, darker and va- 

 riegated with different shades of brown. It resists the most intense 

 heat and is used in the erection of furnace hearths, for which it 

 is most admirably fitted — a few miles above Portsmouth, near the 

 river, this deposit is found on the tops of the hills. — 80 feet. 



8. Argillaceous iron ore, in nodules and lumps, generally kidney 

 shaped and flattened ; imbedded in marl or fine clay, beneath the 

 ore, there is usually a thin stratum of lime. It is a rich ore yield- 

 ing forty or fifty per cent of the best quality of foundery, or cast- 

 iron. — Bed 1 foot. 



9. Sandstone rock, rather coarser than the bed above — grains 

 more flattened and containing some mica. — 80 feet. 



10. Bituminous coal of a good quality, and two feet in thickness, 

 has lying over it a bed of shale of four feet, with vegetable impres- 

 sions between the layers, and below it a bed of dark colored marl 

 and ochre, changing gradually into sandstone the entire carbonace- 

 ous deposit of coal and shale. — 7 feet. 



11. Argillaceous sandstone, light brown, and compact — affording 

 good materials for architectural purposes. — 75 feet. 



12. Siliceous, or sandy iron ore, affording a less quantity of iron, 

 than either of the other ores, and not much used where the others 

 can be procured. — 1^ feet. 



