A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . r, level, mag-nifying lens, measure for wire gauze, plummet, platina scales of various kinds, and an ane-mometer. Tiie traveller can ascertain by its means the temperature, the force of the wind,the latitude, the position of the rocks, or survey and map his route. The geologist can de-termine and draw the direction and amount of dip of the rocks, the angles of cleavage andcrystallization, the temperature of springs, or examine by a plate of tourmaline the bottom
A supplement to Ures Dictionary of Arts, Manufactures, and Mines, : containing a clear exposition of their principles and practice. . r, level, mag-nifying lens, measure for wire gauze, plummet, platina scales of various kinds, and an ane-mometer. Tiie traveller can ascertain by its means the temperature, the force of the wind,the latitude, the position of the rocks, or survey and map his route. The geologist can de-termine and draw the direction and amount of dip of the rocks, the angles of cleavage andcrystallization, the temperature of springs, or examine by a plate of tourmaline the bottomsof pools or shallow depths along coast lines otherwise invisible to the eye. The miner cansurvey and level the roof or floor of his workings, and requires only a pencil to map themupon paper. He can ascertain the temperature of the air under ground, discover whetherthe ventilation is deficient, or see whether the wires of his Davy lamp are in safe condition. Figs. 429, 430 represent the plan and side view of the metra when open and readyfor use. A is the double compass, and b the level. The arc of the level is graduated in 429. degrees, and in inches fall per yard, c the sights ; d the scales; e the goniometer; e thegoniometer scale ; f the plummet; g the lens, witli a telesc()!)ic slide underneath to meas-ure wire gauze ; ii the tourmaline ; j the pivots on which the instrument stands ; k are thetwo joints of the brass leg, by which the horizontality of the instrument can be obtained ; 750 MINERAL CANDLES. L is a flai chisel point for entering joints of rocks or masonry. This end unscrews, expos-ing a wood-screw, (shown by the dotted lines m,) by which the leg can be secured to a treeor stand ; N is the tliermometer, which, like the compass and level, will read correctly tohalf a degree ; o is the screw which holds the top and bottom of the instrument togetherwhen they are opened out for use, as in the drawing. Beneath the bottom cover p areplaced the anemometer, which consis
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Keywords: ., bookcentury1800, bookdecade1860, bookpublishernewyo, bookyear1864
