122 NEW YORK STATE MUSEUM 
illustrated with many diagrams (one of which is reproduced in 
fig. 12) showing the manner in which the ore body was affected 
on different levels by the fault. 
Ruttman believed the ore to be of sedimentary origin and thought 
its form to be due to the original contour of the “ basin” in which 
the “ ore-sediment ” was deposited. 
Putnam *™ described the condition of the mine and the method of 
working the deposit which obtained prior to 1880, and included in 
his report a diagram showing plan and elevation of the workings. 
He likewise gave rather complete analyses of the ore which are of 
sufficient interest to reproduce. Sample no. 738 was taken from 
the 300-foot level; no. 743 was taken from the cars, representing ore 
from the 110-foot level. These are as follows: 
Oe ass. 
SSS ee 
No. 738 No. 743 
Tromp Ie: NEE SOOROT POT TEOMA SERIE ORIE UIE EA 48.91 49.66 
Sl Hur peu tah Seuss ae rs iM relied ay OR RN bar he a i 0.548 0.538 
NOS TOOTS i erenc ke OOS ysis ahetbe asus CAPE RaCies ROMs Gea a 0.015 0.007 
SUIS PLO OE CE eee ERE MEA ESAS tol Up 12.18 10. 81 
YaUbbagihol=ha ih ee Mem Rae shu tac Y ele teeta Tt TIN Tre COMM ean ae 0.79 Tied 
MEAT SAN OUS ORIG Ce epics coat cc a pe Run a eet eA 0.10 0.04 
Damen eO ee. AREAL VASO ORE URS TS RR TIA AOL DT NSO Cy 3.10 1.19 
Wiese sian s Uciabinl de ne well sia hia paul i. MU ARN Ae ie Talo 16.33 
Car boniGiroxra en CU MOMMA a anM setae: e mnU icy ents ee eee Ie es 0.40 0.28 
The striking feature in these analyses is of course the high per- 
centage of magnesia, and the lime, as contrasted with the lower per- 
centage of silica; the combination being of such a nature as to make 
a “self-fluxing” ore which was regarded as especially valuable. 
Owing to the dangerous condition of the roof of the mine it was 
decided to uncover it, and this work was begun in 18877. When 
finally uncovered, the mine, as stated previously, was worked as an 
open pit until it was abandoned in 1897. Landis 1° described the 
methods employed in operating the mine after the cover had been 
removed, but none of the earlier students of this deposit seemed to 
attach any importance to the unusual minerals in the ore, such as 
174 Putnam, B. T. Tenth Census Report, 1880. 
175 Smock, J. C. N. Y. State Mus. Bul. 7. 1889. See also McDowell, F. 
H. Trans. A. I. M. E. v. 17, 1889, and Eng. and Min. Jour. Sept. 7, 1880. 
176 Tandis, EF. K. The Tilly Foster Mine Jour. Frank. Inst. v..CL, p. 223- 
26. 1900. 
