Page:Popular Science Monthly Volume 89.djvu/248

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��Popular Science MoiifJiIi/

���This big dump of culm coal is on fire, although there are no visible signs of it. A trench is being cut across the pile to restrict the fire to its present field and prevent it from spreading

��Coal-Dust "Mountains" are Now Repositories of Wealth

IN the anthracite mining region of Pennsylvania there are real ranges of hills, almost mountains, of pure coal. These are the piles of culm or coal-dust screenings, which, imdcr former methods of mining, were thrown out as so much waste. There are millions of tons of this culm, and modern furnaces arc now using it. Culm is not only screened and burned as by-coal, a "dust," but is also pressed into briquettes. Modern coal- dust burning locomotives are using it as pulverized fuel. As such it is of perma- nent value.

The photograph shows a large culm dump near Scranton, Pennsyhania, which has caught afire. Once a fire gains good lieadway it is extremely difli- cult to extinguish; it burrows down into the very heart of the pile and then works its way along laterally. A few years ago this culm pile would have been allowed to burn itself out as a worthless property. Now it is being sa\-ed, as

��shown in the picture, by cutting a trench across the pile to check the progress of the fire. Although the photograph gives no \isible e^■idence of a fire, proximity to the radiating heat of the pile would prove to liie onlooker that the interior is a veritable inferno.

��A Damaged Lock - Gate Repaired by Its Own Water

WATER swirling out of the locks at Suult Ste. Marie damaged one of the gates so badly that the canal engi- neers despaired; but the trouble was sin- gularly righted by allowing water to rush in again. A ship had jiassed out of the canal, and the lock was allowed to drain, but one of the gates was closed too soon, was caught in the rusliing water, and bulTeteil so rougiih- that the top was s|)rung more than a foot out of plumb. Several unsuccessful attempts were made to repair (he sagging gate b>' means of jacks and turntables. Mean- while, a long line of ships from the North and South was inipalicntly gathering.

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