418 GEOLOGY OF THE SECOND DISTRICT. 



CHAPTER, XI. 



Some of the common substances tvliich may he employed for economkal purposes. 



Economical materials existing in the form op rocks. 



Mantels, Centre tables, etc. Hypcrslhene rock, forming in many instances a beautiful 

 material in which the elements are homogeneous, or combined with great equality, may with- 

 out doubt be manufactured into the richest and most durable patterns for mantel pieces and 

 ornamental tables of various kinds. In this rock there arc several varieties, which differ in 

 color principally as it regards a light and dark ground, and the distribution thereon of crystals 

 of labradorite. The varieties with a light ground arc generally opalescent, or at least this 

 quality appears in them to better advantage than in those with a dark ground, in wliicli the 

 opalescence is observed with difficulty. There can be but little doubt but that this material can 

 l)e obtained in a form and condition which will meet with a sale. Mr. Henderson, while 

 superintending some improvements in the reduction of iron ore, placed a block of liypersthcnc 

 so as to be acted upon by a short common saw which was moved by the machinery of a mill, 

 and found that it cut into the block to the depth of two inches during the day. At that rate, 

 a gang of saws would in a short time cut out slabs suitable for tables or mantel pieces of the 

 ordinary size. Should these opinions be found correct, after some farther experiments, one 

 more source of private enterprise will be opened. This rock is confined to Esse.x county. 



Lime, and Mortar. I have ascertained that limestone exists in all parts of the district ; and 

 I am of the opinion that it may be found, if not in every township, at least within a short 

 distance therefrom. It was made a special object of search wherever I went. Some diffi- 

 culty, however, was experienced in finding it in the w"ooded and unsettled districts. It rises 

 in the midst of the hypersthene rock, in tiie form of beds or veins ; and it is common in the 

 granite and gneiss districts, in the same condition. Hence there will be an abundant supply 

 of lime for mortar, and for agricultural and domestic purposes. The primary limestone is 

 rarely suitable for any other purpose than the manufacture of lime, for it is too liable to dis- 

 integration to be used as a marble or building material. The Champlain group furnishes 

 several limestones suitable for marble. The rock beneath the trenton occurs at several places, 

 and also the tliick layers of the birdseyc upon the Great bend of the Black river, and at Chazy. 



