Collection: Books and Periodicals > Nevada County Historical Society Bulletins

About This Item:

Title: Volume 045-4 - October 1991 Collection Type: Books and Periodicals Collection Name: Nevada County Historical Society Bulletins # of Pages: 8 Download PDF: User Login Required Download OCR Text: User Login Required

Date Scanned: 2014-02-19 07:59:22 OCR Software Version #: tesseract 5.4.1 Item Sourced From: PDF First Created: 2025-03-17 04:05:59 Last Updated: 2025-03-17 04:05:59

Original Held At: Searls Historical Library Location: 161 Nevada City Hwy, Nevada City, CA 95959

Page: of 8  

to provide power for the North Star in the same manner. Some of the early Pelton wheels were made of wood with metal buckets. An example of such a wheel, originally from the Davis mine, is shown in the museum. Such wheels were not very satisfactory; it was very difficult to keep the buckets tight on the wheel since large forces were at work. In 1970, the collection of mining artifacts was transferred from the Mill Street museum to the power house: the beginning of the present museum. At that time, the Pelton wheel was not enclosed; many photographs show the museum in this state. At a later time, the building was completely enclosed to protect the wheel and the other artifacts from the weather. The Grass Valley Mining Museum is the most complete one, illustrating hard rock mining, in the Gold Country. This eminence was made possible by the generosity of Mr. Dowdell and many others who donated artifacts. But of equal importance are the many hours of hard work, donated by its director and his helpers, without their work, the museum could never have become what you see now. In this article, some of the museum's exhibits will be pictured and described. Some others already have been described in former Bulletins of the Historical Society, and will therefore be only mentioned in this text. Still available issues of the Bulletin of the Nevada County Historical Society, which are of mining interest, are: Oct. 1956 and Sept. 1964 (Hydraulic mining) April 1961 (The Pelton waterwheel), to be seen in the museum. May 1961 and May 1963 (The Empire Mine) Nov. 1963 (The North Star Power plant), the present building of the museum. Oct. 1968 (The Mining Museum at Mill Street) April 1979 (The Cornish pump outside the building) Underground, there was an entire world. One entered through a shaft, which was either inclined or vertical. From the shaft sprung horizontal tunnels, or drifts, if they went up and did not surface, a raise. Various levels in the mine were connected by non-surfacing shafts, called winzes. The shafts and the drifts were fairly narrow, but at some places, where the actual ore was recovered, there were larger areas, called stopes. Shafts were made by blasting and removing the debris by hand. Around the middle thirties, the engineers at the Idaho Maryland decided to produce a shaft by boring. A shaft, made this way would have many advantages, among them smooth walls. They constructed a cylindrical drill, 5 feet in diameter, and successfully bored a shaft, 1125 feet deep. Inside this cylindrical drill, a core was formed, which was removed piece by piece. A part of this core can be seen outside the museum. Although it was claimed that this experiment was successful, the method was apparently not widely adopted. A discussion of this experiment will be found in the NCHS Bulletin for February 1962. 26 The miners descended into the mine in a man skip, one of which is seen outside the museum. At the right of the museum entrance is a picture of miners, entering the No. 1 shaft of the Idaho Maryland mine in this skip. This shaft entered the mine at an angle of 72 degrees and had a depth of 1500 feet; the descent took about two minutes. The men were sitting on removable seats, putting their legs over the shoulders of the man below. The seats were removable so that the skip could be used for timber or other supplies for the mine. MAN SKIP The man skips and ore cars moved in the mines on Tails em These rails extended outside the mine on a huge frame the head frame. Behind the large Pelton wheel, there is a model of such a head frame, on which the rails are arranged in such a way that the ore cars automatically io