22 ECONOMIC GKOLOGY. 



TriE GiJAFTON Company. 



One of the curiosities of mining in New Hampshire has been illus- 

 trated by the history of the Grafton Gold Mining Company, organized 

 near the beginning of tlie year 1869. Tlie property is near the west 

 corner of Lyman. It was first known as the Davis & Thayer, and after- 

 wards as the Wiggin & Davis property. I visited it September 14, 1868, 

 and May 10, 1869. It lies in the Iluronian rocks east of Gardner's 

 mountain, tlie material being dolomitic and somewhat slaty. At the sur- 

 face three veins, each about a foot in width, showed themselves, with 

 narrow .slaty parting.s, which became smaller at 25 feet, and are said to 

 have entirely disappeared at the depth of 76 feet, — the bottom of the 

 shaft, — and to be 8 feet wide. The veins incline soutli-easterly 55" at 

 the surface, and 10° less at the depth of 25 feet, the lowest point at which 

 I have seen it. The vein is of limpid quartz, with many crystals of quartz, 

 dolomite or ankerite, iron pyrites, and galena, besides some free gold, the 

 latter most abundant in the upper vein. An immense number of segre- 

 gated quartz veins ramify through the dolomitic mass that is brought to 

 the surface. 



I'^rom several statements shown me by officers of the company, it ap- 

 pears that the earlier assays gave over $y of gold to the ton of rock; and 

 at the depth of 76 feet, out of a mass weighing 50 pounds. Dr. Torrey, of 

 New York, obtained gold at the rate of ^62.17 to the ton, and of silver, 

 ^1.33. An examination of the pyrites showed no gold present. About 

 forty per cent, of the gangue was shown to be of quartz, and the balance 

 chiefly dolomitic. A careful examination of a similar sample by T. C. 

 Raymond, of Cambridgeport, Mass., gave the following result: Silica, 

 30.3; protoxide of iron, 6.27; lime, 20.6; magnesia, 11. 17; carbonic acid, 

 22.1 1 ; — total, 100.44. This composition led the company to believe that 

 the pulverized rock might be used advantageously as a fertilizer after the 

 extraction of the gold ; and some experiments were instituted to show 

 its value. 



The i)roprietors drove a thriving business in selling this pulverized 

 siliceous dolomite for a fertilizer. Even those rei)uted agricultural writ- 

 ers of eminence became interested, and saw great benefits to the soil in 

 the application of this powder. No doubt some benefit came, from the 



