Page:Popular Science Monthly Volume 91.djvu/720

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��Popular Science Monthly

���unnecessary top cross-braces and attaching an overflow spout near the top of one end. The operation of this instrument is very- simple, being based upon the principle that a submerged body displaces a volume of water equal to its own solid contents. The tank is filled with water to the overflow spout; then the wood material to be meas- ured is submerged. The displaced volume of water escaping through the opening or overflow represents the exact volume of the submerged -material.

Some of the results concerning wood waste secured by the use of this instru- ment are almost incredible. For example : a white pine tree, which in its original condition comprised 25.05 cubic feet of wood and bark, was converted into shingles. It yielded 603 shingles (4 x 21 inches) which displaced 11.86 cubic feet- of water, showing that only 47.3 per cent of the wood originally in the tree remained in the finished product. The exact percentage of waste would be difficult, if not impossible, to obtain by other means. — J. S. Illick.

��Submerging billets of wood. The water dis- placed and forced out into the graduated pail will be equal to the solid contents of the wood

Here Is the Xylometer. It Measures the Waste in Wood Products

THERE has always been a large amount of waste in converting a tree into lumber and other products. The first logical step in the reduction of this waste is an accurate determination of the amount of waste and a careful study of the process of manufacture and remanufacture. A xylometer offers the most practical means of determining the percentage of waste and may be of inestimable value to the forester, woodsman and mill operator at- tempting a closer utilization of forest products.

The xylometer is an instrument which is not well-known in America but which has been in use for years in European countries.

The type here shown was improvised from an ordi nary round- end galva- nized steel storage tank by removing a number of

���The automatic engine. Its speed is adjustable. Even the cooling is automatic, the flywheel whirling air into the engine base like a centrifugal fan

��The Simplified Gasoline Engine. It's the Hired Girl of the Country

THIS miniature motor is the house- wife's faithful laundress, churner, etc. It can be operated with as much success by a child as by an adult. One turn of the light flywheel and the engine starts off. By simply turning the thumbscrew over the main bearing, its speed is adjusted.

The cylinder of the motor is inverted. This allows the gasoline to flow from its tank directly into contact with the electric spark caused by the spark coil of the igni- tion system. The result is that some gas will immedi- ately explode and the en- gine can be quickly started even in the cold- est weather. The inver- sion of the cylinder, moreover, makes it a simple mat- ter to enclose its hot end in an iron housing, out of the way of the children's fingers.

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