Page:Popular Science Monthly Volume 91.djvu/754

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��Popular Science Monthly

���Small as this locomotive seems it can pull a train of eighteen cars, each loaded with 3% tons of lumber

��couplings consisting of heavy rods seven or eight feet in length with a hook at each end, fasten into the coupler bars of each car, resulting in about a three-yard spacing between successive cars when they are connected.

This spacing is necessary because the lumber being transported overhangs each car body to so great a degree. The three locomotives, small though they look, do work that would otherwise require more than twenty horses. Moreover they don't eat any hay when off duty.

��Diminutive Electric Locomotives Used in a Lumber-Mill Yard

SMALL electric locomotives of a kind every youthful mechanic in the country would yearn to run are being used by a large western lumber mill to transport raw and finished lumber about its plant. The locomotives run on a three-foot track, and there are upwards of forty miles of it scattered around the big mill.

The locomotives for this service are really standard mine locomotives per- suaded to run on top of the ground instead of under it, and disguised a bit by the erection of a steel cab at one end. Reg- ular mine locomotives cannot as a rule afford this luxury since the low-hanging roofs of mine tunnels would in all proba- bility scrape it off.

Storage batteries carried on the loco- motives themselves furnish the power. During the night when the machines are off duty the batteries receive the charge that is to last them through the next day. The locomotives are more powerful than their dimin- utive size would lead one to ex- pect. On a level stretch each can readily pull a train of eighteen small cars loaded with about three and a half tonaof lumber each. Unusually long

��o

��Less volatile fuel

elements strike

heated wall, are vaporized and then flow with more volatile elements

to cylinders

���Getting More Mileage Out of Gaso- line with the Hot-Point Manifold

NE of the most successful means worked out for giving an increased mileage per gallon of gasoline in automobiles since the fuel problem became so acute, is the hot-point manifold. The hot-point manifold consists of a tube, made a part of the cylinder head in the case shown, which is water-jacketed throughout its entire surface, except the ends and a wall on the inner side at the middle.

The incoming air passing through the Venturi of the carbureter picks up a suitable amount of fuel. With the present low grade of fuel, which is part kerosene and part gasoline, the heavy kerosene elements do not volatilize or change into gas as readily as the gasoline constituents. The' kerosene portion enters the manifold in globules or small drops, and these, due to their weight, dart directly across the

��Heated wall exhaust Water

��rtore volatile elementsflow into cylinders .without striking 1 heated walls

��Valve push-rod

��fully carbureted fuel gases into cylinders

��The hot-point manifold is near enough to the cylinders to prevent recondensation of kerosene

��manifold and im- pinge on the hot surface. From contact with the heated metallic surface they are thrown off in gas and mix readily with the ingoing air and lighter gasoline fuel elements. The hot point of the manifold pre- vents reconden- sation.

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