264 
CEMENT MATERIALS AND INDUSTRY. 
[bull. 243. 
in 1898 the Helderberg Cement Company began to utilize the ston 
from these latter quarries in the manufacture of Portland cemen 
Commenced on a small scale, the industry would seem to have prom 
ised favorable results, as a much larger plant, belonging to the sain 
company, was erected during 1900 and has recently started operations 
The new plant has a nominal capacity of 1,500 barrels a day. The 
materials used are limestone and clay. 
As noted below, the limestone used for Portland cement is obtained 
from the old lime quarries and the clay from a Quaternary deposit in 
the vicinity. Smidth ball mills and Davidsen tube mills are used for 
crushing, reducing, and mixing the materials. The wet process 
employed, and twelve rotary kilns are in use. The resulting clinke 
is ground in ball mills and tube mills, and the product is marketed as 
the "Helderberg" brand. 
The limestone used in Portland-cement manufacture is obtained 
from the Becraft and Manlius beds, exposed in quarries just west of 
the station, on the northern side of the railroad track. Partial analy- 
ses of these limestones, quoted by Prosser as having been made by. 
C. A. Schaeffer, follow. 
Analyses of limestones used at Howes Cave, N. Y. 
Manlius limestone 
Becraft limestone. 
SiOo 
1.48 
4.12 
Ca( '( ), 
95.75. 
93. 68 
Another sample analyzed by Schaeffer gave the results stated below. 
Analysis of limestone used for making cement at Howes Cave, N. Y. 
Silica (Si0 2 ) 1.27 
Alumina ( A1. 2 3 ) "& 
Iron oxide (Fe 2 3 ) I 
Lime carbonate (CaC0 3 ) 97.24 
Magnesium carbonate ( MgC0 3 ) 1. m 
Sulphur trioxide (S0 3 ) Trace, 
The plant of the Hudson Portland Cement Company is located iui 
the city of Hudson, Columbia County, and is therefore the only cemenfif 
plant in the United States situated east of the Hudson River. The 
limestone used here is obtained a few miles from the plant from ar 
outlying area of the Becraft (lower Helderberg) limestone, known as 
Becraft Mountain. Quaternary clays and shales of Hudson (Ordovi 
cian) age are used to complete the mixture. The plant itself was 
recently constructed, and at present ten kilns are operated. Analyse: 
by Herberg and Roney of the clays and shales used here follow. 
