HYDROLOGY. I57 



1. Drift 92 feet. 



2. From 92 to 300 feet, a hard, bluish-grey, close-textured, semi-crystalline magtiesian 

 limestone. A few scales of sesqui oxide of iron present. 



3. At 300 feet, reddish, calcareous clay, containing angular fragments of limestone 

 and sesqui oxide of iron. 



4. At 308 feet, chiefly red siHcious sand of varying coarseness, mixed with fragments 

 of dark shale. 



5. At 400 feet, light orange, silicious sand, the constituent grains of which are irregu- 

 lar in form and surface. White clay-hke fragments, appearing like kaoKn, and iusolu- 

 ble ia hydrochloric acid, probably chippings of soft chert, also present. 



6. At 416 feet, dirty red sand, mingled with fragments of magnesian hmestone, and 

 also lumps of sand and limestone cemented with a reddish or whitish calcareous clay. 



7. At 425 feet, white and orange, rather coarse, silicious sand, and a httle of the kaolin- 

 like material, almost all the fragments of which are marked upon one side by metaUic 

 iron, e-vidently from the drill, showhig that they were clipped with difficulty from a 

 larger mass. 



8. At 435 feet, yellowish-orange, sihcious sand; the grains of medium size, and numer- 

 ously marked with adherent specks of oxide of iron. Many fragments of chert drillings, 

 marked with metallic iron, also present. 



9. At 500 feet, very fine grained siHcious sand; a few minute lumps consisting of grains 

 of sand cemented by finer material; no efi'ervescence in heated or cold hydrochloric 

 acid; color, yellowish white; some chert drillings present. 



10. At 557 feet, driUings light pinkish grey, appearing Uke crystalline powder. Ex- 

 amined under microscope, found to be composed of grains of limpid quartz and particles 

 of chert associated with the more finely powdered material that gives rise to the color. 

 No effervescence when tested with cold or hot hydrochloric acid. 



11. From 580 feet to 618 feet, the drillings are similar to the above, but the qu,Txtz 

 grains are larger, more numerous and conspicuous, and the finer material is white. 

 A very small amount of oxide of iron is present. No action when treated with acid. 



12. From 685 feet to 695 feet, orthoclase feldspar predominates, attended by consid- 

 erable quartz and a less quantity of a dark mi neral, probably hornblende. 



Classified, the two sections become: 



At Hospital. 



Drift 60 feet. 



Limestone 240 



Sandstone 414 " 



Granite rock 248 



Total 961 feet. 



The correspondence between the two is quite marked. In the 

 southwestern portion of the city the rock of the region is exposed in 

 quarries at an elevation very nearly the same as the surface at these 

 wells. This rock is clearly shown by its fossils to belong to the Ga- 

 lena limestone, in the modified character which that formation bears 

 in this region. It is seemingly the lower portion of the formation, 

 and there is good reason for believing it to be entirely wanting at the 

 locality of the wells where the drift is deep. The lower strata of the 

 Trenton limestone are found at the surface at a distance of less than 



