220 NEW YORK STATE MUSEUM 



Feet 



8600 To Broadway — ^^lanhattan schist (little known except 

 from tunnels already made) 

 14000 To East river, probobly ^Manhattan schist (same as line A) 

 6000 Manhattan island to City Hall, Brooklyn — uncertain con- 

 dition (same as on line A) 



SUMMARY OF LINE B 

 Feet 



8000 Yonkers gneiss — good quality 

 13000 Fordham gneiss — good quality 

 21 400 Inwood limestone — variable quality 

 12 800 Manhattan schist — good quality 

 23 400 Estimated ]\Ianhattan schist — fair 



6 000 Almost unknown 



84 600 total 



Line C. Going south from Hill View reservoir 



Feet 



6000 Yonkers gneiss — good rock 

 17400 To Webster av. — Fordham gneiss — good rock 



5 000 Along contact between limestone and gneiss 



9 800 To 138th St. — Inwood limestone with probably t\vo bad 



zones 

 I 800 To Bronx kills — along contact between limestone and 



gneiss — uncertain quality 

 600 Across Bronx kills — mostly in limestone containing a 



fault zone — ■ probably bad ground 



6 400 Crossing Randall's and Ward's islands and Little Hell Gate. 



Xearly all is ^Manhattan schist of good qualit}^ 

 I 000 Crossing Hell Gate — Inwood limestone 

 I 200 Crossing Hell Gate — Fordham gneiss of good quality 

 I 800 Astoria point — probably Fordham gneiss of good quality 

 I 000 Crossing another limestone belt 



1 000 To \^ernon av. — Fordham gneiss of unknown quality con- 



taining one fault zone 



7 000 To Xott av. — Ravenswood grano-diorite — good rock 



2 800 To Borden av. — Probably Ravenswood grano-diorite. 

 18400 To Fort Greene Park Brooklyn — almost wholly unknown 



but contains probably 5000 or 6000 feet of poor ground 



