232 GEOLOGY OF THE SECOND DISTRICT. 



and towards the boundaries of the vein, it is only a mere apology for a vein of ore. The 

 annexed diasn-am is introduced to illustrate this feature : 



° 61. 



a, rich central part ; 6, expanded portion ; c, adjacent gneiss. 



The rock inclosing this vein dips to the southeast, and the vein itself dips nearly southeast. 



The vein is explored along the top to the open day, and it is blasted or quarried out like 

 any other rock. The limits of the vein north and south have not been ascertained ; it is con- 

 cealed in both directions by soil, and the debris of neighboring rocks. 



This vein furnishes an excellent material for bar iron, and is reduced without difficulty in 

 the forge. The vein is very free from sulphuret of iron, and the quartz matrix forms a slag 

 which escapes freely from the loup, without danger to its safe welding. This is the usual 

 result when quartz is the gangue ; and it may be looked upon as a sure indication, that where- 

 evcr quartz forms the gangue of a vein, the ore will work readily in the forge, and princi- 

 pally because of the perfect and clean separation of the slag or melted earthy materials from 

 the iron. 



In order that the value of the ores of New-York may be more extensively known and better 

 appreciated by the community, I shall furnish some authentic testimonials of their qualities, 

 which may be depended upon as testing their relative value and utility. With this view, I 

 here copy an account of several experiments which were instituted by the National Govern- 

 ment for determining the strength of the Crown-Point iron, on samples manufactured from 



the ore of the vein under consideration : 



COMMANDANT'S OFFICE, 1 

 Navy Yard, Washington, June 13, 1829. J 



Sir — Agreeable to your direction, I yesterday proved the sample of iron furnished by Messrs. Pen- 

 field & Taft, and found it of superior quality; perhaps the best that has ever been proved at this Yard. 

 As I had the ten fathoms of chain cable made for trial from iron furnished by Messrs. Holly & Co., I 

 considered it a good opportunity to try them together, by which means I could ascertain the relative 

 strength of each, and have a fair trial what proof they woidd bear. I therefore connected them by 

 large iron, with a shackle or end link of a very large size, which I now send you. The large link 

 parted with 384 lbs. on the lever, as stated in the accompanying report. On a second trial, Mes.srs. 

 Pcnfif'ld 6l Taft's chain parted that of Messrs. Holly & Coffin's witli 418 lbs., which clearly proves 

 that both samples are of superior iron, and that Messrs. Penfield &, Taft's is best, so far as our experi- 

 ments have gone. ISAAC HULL. 

 To THE President of the Navy Board. 



