Up Balances and Scales Prev Next Slideshow

 Previous image  Next image  Index page  Original Image [Pulp Balance II with Weights.JPG - 1.2MB]
Gold Scale
Herman Kohlbusch May 1902 Engineering and Mining Journal
Kohlbusch Scale I
Kohlbusch Scale II
Kohlbusch Scale III
  Pulp Balance II with Weights.JPG - L. E. KNOTT PULP BALANCE - Pulp balance; L. E. Knott Apparatus Co., Boston,circa 1880, used in Silverton area, acquired from Silverton resident  (A number of balances were used in the assaying of ore and the pulp balance is one of them.  The pulp balance shown here is the enclosed style while others were the open style.  The enclosed pulp balance was also called an analytical balance and was constructed of a wood case, oftentimes mahagony, with glass sides and top and a sliding front glass panel for access.  The enclosed balance had pan rests to control oscillations when in use.  The pulp balance was used in the assaying process to weigh the "pulp" which is the result of crushing, quartering and screening the ore.  At this stage in the process, the assay ton weights were used.  Since gold and silver assays were reported in troy ounces per ton, if the pulp was weighed in grams and the button in milligrams (the button is a small pellet of the metal of interest that results from the assaying process), the assayer would need several calculations to do the conversion to troy onces per ton.  The system of assay ton weights greatly simplified this computation.  Simply, one assay ton weighs 29,166 milligrams, the same milligrams as there are troy onces in an avoirdupois ton.  If the ore charge of one assay ton is taken, each milligram that the resulting metal button weighs represents one troy ounce of the metal per ton of ore.  Two different sets of assay ton weights were generally available, one set ranging from one assay ton to 1/20th assay ton, and a second set from 4 assay tons to 1/20th assay ton.  See Shannon, Mining Artifact Collector #4, p 33)  
Miners Gold Scale Closed
Miners Gold Scale Contents
Miners Gold Scale Open
Miners' Improved Gold Scale Closed
Miners' Improved Gold Scale Open

Pulp Balance II with Weights | L. E. KNOTT PULP BALANCE - Pulp balance; L. E. Knott Apparatus Co., Boston, circa 1880, used in Silverton area, acquired from Silverton resident (A number of balances were used in the assaying of ore and the pulp balance is one of them. The pulp balance shown here is the enclosed style while others were the open style. The enclosed pulp balance was also called an analytical balance and was constructed of a wood case, oftentimes mahagony, with glass sides and top and a sliding front glass panel for access. The enclosed balance had pan rests to control oscillations when in use. The pulp balance was used in the assaying process to weigh the "pulp" which is the result of crushing, quartering and screening the ore. At this stage in the process, the assay ton weights were used. Since gold and silver assays were reported in troy ounces per ton, if the pulp was weighed in grams and the button in milligrams (the button is a small pellet of the metal of interest that results from the assaying process), the assayer would need several calculations to do the conversion to troy onces per ton. The system of assay ton weights greatly simplified this computation. Simply, one assay ton weighs 29,166 milligrams, the same milligrams as there are troy onces in an avoirdupois ton. If the ore charge of one assay ton is taken, each milligram that the resulting metal button weighs represents one troy ounce of the metal per ton of ore. Two different sets of assay ton weights were generally available, one set ranging from one assay ton to 1/20th assay ton, and a second set from 4 assay tons to 1/20th assay ton. See Shannon, Mining Artifact Collector #4, p 33) Download Original Image
Total images: 63 | Last update: 5/1/15 3:53 PM | Help