. Journal. The walls of the vat areconstructed of iron rods embedded in a concrete com-posed of river pebbles, sand and cement; a similar concreteis stamped on the foundation prepared for the bottomof the vat. The whole of the inside of the vat is ooiwith a layer of pure cement so worked with the trowel thatit presents a perfectly smooth, non-porous surface. Thecement vat is kept moist for 14 days, and then full ofwater for four weeks. After that it is emptied and driedby the careful application of a hand soldering lamp until thewhole vat is warm to the touch. Then melted paraffin,at a tempera

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. Journal. The walls of the vat areconstructed of iron rods embedded in a concrete com-posed of river pebbles, sand and cement; a similar concreteis stamped on the foundation prepared for the bottomof the vat. The whole of the inside of the vat is ooiwith a layer of pure cement so worked with the trowel thatit presents a perfectly smooth, non-porous surface. Thecement vat is kept moist for 14 days, and then full ofwater for four weeks. After that it is emptied and driedby the careful application of a hand soldering lamp until thewhole vat is warm to the touch. Then melted paraffin,at a temperature of 120° C.,is applied all over with a brush,the paraffin is driven into the pores of the cement byfusion with the hand lamp, then a second coat is applied,and finished on* smootli with the lamp.—J. F. B. I i i I Halt Kilns; Imjptt. in ,,,A Uoll Austria, Pa I , . t. 21, 1904 Thk green mall is fed through a hopper, 7. Incleansing drum 9 i Kg, _). i ibetween two pei forated oylini. (ZZitX &/;///////////////// ://,

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Keywords: ., bookcentury1800, bookdecade1880, booksubjectchemist, bookyear1882