. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. ; 2. the^raduated semi-circle, which serves to measure the inclination, which isalso called the clikjmeter. 3. The chain or«ord for measuring the distance of one point from another. 4. When the neihborhood of iron renders the use of the magnet uncertain, a plate orplane table is emploed. The dials of the Cmpasses generally used in the most celebrated mines, are graduatedinto hours ; most coimonly into twice 12 hours, t^ius the whole limb is divided into24 spaces, each of hich contai
. A dictionary of arts, manufactures and mines : containing a clear exposition of their principles and practice. ; 2. the^raduated semi-circle, which serves to measure the inclination, which isalso called the clikjmeter. 3. The chain or«ord for measuring the distance of one point from another. 4. When the neihborhood of iron renders the use of the magnet uncertain, a plate orplane table is emploed. The dials of the Cmpasses generally used in the most celebrated mines, are graduatedinto hours ; most coimonly into twice 12 hours, t^ius the whole limb is divided into24 spaces, each of hich contains 15° = 1 hour. Each hour is subdivided into 8parts. Means of penetratingnto the interior of the earth.—In order to penetrate into the inte-rior of the earth, and tOjxtract from it the objects of his toils, the miner has at his dis-posal several means, wlch may be divided into three classes; 1. manual tools, 2. gun-powder, and 3. fire. The tools used by the n^ers of Cornwall and Devonshire are the following: Fig. 700. The pick. Its a light tool, and somewhat varied in shape according to cir-703 702 700. cumstances. One side used as a hamma: is ^Ugj} the poll, and is employed to drive inthe gads, or to loosen and detach prominences, jjjg p^^^^f jg ^f g^gg]^ carefully tempered,and drawn under the hammer to the prober form jj^g Fjendi ^all it pointerolle. 842 MINES. Fig. 70 J. The gad. It is a wedge of steel, driven into crevices of rocks, or into smallopenings made with the point of the pick. Fig, 702. The miners shovel. It has a pointed form, to enable it to penetrate amongthe coarse and hard fragments of the mine rubbish. Its handle being somewhat bent, amans power may be conveniently applied without bending his body. The blasting or shooting tools are :— A sledge or malletBorer Claying barNeedle or nailScraperTamping bar fig- 703. — 704. — 705. — 706. — 707. — 708.
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Keywords: ., bookcentury1800, bookdecade1840, booksubje, booksubjecttechnology
