Johnson and Warren — Geology of Rhode Island. 3 



32 per cent) in the rock and the high percentage of titanium 

 appear to have prevented any considerable use of it for the 

 production of iron notwithstanding the enormous amount easily 

 available. 



More recently, the " Cumberland Iron Trap Rock Company" 

 attempted to work the deposits for road-metal and erected a 

 plant for crushing the rock, but for one reason or another the 

 enterprise failed. 



Many references to the geology, petrology, and economic 

 aspects of the cumberlandite may be found in the literature. 

 For a list of the more important papers the reader is referred 

 to the bibliography which will be found at the end of the 

 article. 



Dr. Robinson, in his book entitled "A Catalog of American 

 Minerals, with their localities," published about 1825, writes 

 under " Cumberland, R. I., magnetic oxide of iron ; two miles 

 N.N.E. of the meeting house on the left of the Wrentham 

 road, is an immense bed constituting a hill. Most of this ore 

 is a metalliferous porphyry, having crystals of feldspar in the 

 iron." 



Professor Edward Hitchcock in 1833, in his report on the 

 geology of Massachusetts, gives a brief description of the rock 

 and its occurrence. Dr. Charles T. Jackson was, however, the 

 first to give a description of the hill in any detail. In his 

 report on the geology of Rhode Island published in 1840, we 

 find the general dimensions of the hill given and a geological 

 section along a north-south line. He also comments briefly on 

 its origin, expressing the belief that it was "protruded through 

 the granite and gneiss at the same epoch with the elevation 

 of numerous serpentine veins which occur in this vicinity." 

 He gives a chemical analysis, the first, it is believed, that is 

 recorded. 



In 1841 Professor Hitchcock expresses himself as believing 

 that the iron ore should be looked upon as belonging to the 

 metamorphic slates of the region, " or rather lying at their 

 juncture with the unstratified rocks (granites, etc.)." He 

 seems for some reason inclined to the belief that the rock will 

 be found to be strongly impregnated with manganese. 



Benjamin Silliman, Jr., in reviewing Dr. Jackson's book 

 shortly after its publication, appears to agree with him as to 

 its origin, and believes that in this respect it may resemble the 

 iron ores of Missouri. 



In 1869, and again in 1872, Mr. R. H. Thurston published a 

 chemical analysis, the mean of several (source unknown to the 

 author), and seems to have been the first to have mentioned 

 the presence of ilmenite in the rock. Analyses of the ore by 

 one. Dr. Chilton, were also published in the New York Tribune 



