ORES OF THE PRIMARY ROCKS. 
567 
This ore has its bearing and dip corresponding with those of the rock. Only one layer of 
the ore has been worked, which is six feet thick. The ore is strongly magnetic, and said to 
be as good as any in the Highlands. It is associated with hornblende, sahlite, slaty gneiss, 
gneissoid hornblende and reddish granite ; has a small quantity of pyrites requires roasting, 
and gives a red short iron. This mine has been worked three hundred yards in length, and 
about forty in depth. The early working has all caved in, but fine pillars of ore sustain the 
hanging wall where the work has been recently prosecuted. Vast quantities of ore have been 
taken from this mine, without any appearance of its failing. It belongs to the Messrs. 
Townsend. Only one dyke has ever occurred in this mine ; it was one foot thick, and made 
no change in the direction of the ore. It cannot now be seen ; is worked seventy feet deep.* 
“ Long mine was discovered in 1761, by David Jones ; it has never been bottomed in any 
place. It is traced over a mile in length; is wrought forty rods in length; general width 
sixteen feet, consisting of two parallel layers, with a waving slab of rock between them from 
four to twelve inches thick. In this forty rods a dyke has been found, of what Mr. Townsend 
calls an imperfect flint, two feet thick, standing perpendicularly, and crossing the ore at right 
angles ; (it is now covered.) All the ore similar; yield always sixty-two per cent. Average 
amount of ore used, five hundred tons ; this, in seventy-five years, gives thirty-seven thousand 
five hundred tons taken from this mine. Its iron is remarkably tough, clean and strong ; cost 
of mining from fifty cents to one dollar per ton. The iron of Long mine has been much used 
for cannon, muskets, wire, steel, and fine malleable iron. It has also been cast into harness 
buckles, and after annealing, proves exceedingly tough and strong.”! 
Dr. Beck, describing this mine, says,—“ This is situated about five miles southwest of 
Southfield furnace. The ore occurs in gneiss rock, and follows the general direction and dip 
of the strata, and is never at right angles to them. The bed has been very extensively worked ; 
but owing to injudicious management, the old worMngs are at present closed. Recently the 
mining operations have been conducted in a more skilful rhanner. Pillars, or supports of the 
rock or of the ore itself, are left at intervals, while the excavation is continued in a nearly 
horizontal direction. The accompanying rock is exceedingly variable in its character. Some¬ 
times the felspar greatly predominates ; at others, the quartz prevails ; and again at others, 
mica, of a blackish color, is the principal ingredient. The floor of the bed approaches to 
mica slate ; its course is nearly north and south, and its dip to the east. 
“ This ore is of a bluish black color, and has minute grains of quartz disseminated through 
it, which causes it to give fire with steel. It breaks in columnar fragments, and being of a 
granular structure, is without much difficulty reduced to coarse powder; and when in this 
state, it is strongly attracted by the magnet. It does not, however, possess polarity. The 
average specific gravity of the ore is 4*885 ; and with the exception of the siliceous particles, 
it is entirely soluble in hot concentrated muriatic acid. 
“ The results of the analysis of this ore show that it is of an excellent quality. It is highly 
• Dr. Hokton, Third Geological Report of New-York, 1839, pp. 163, 173. 
t Ibid, 1837, p. 19. 
