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Page:Popular Science Monthly Volume 90.djvu/443

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Popular Science Monthly


���A Revolving Barrel as a Concrete Mixer

AN oil barrel suspended b> . chain from a metal frame in such way that the barrel is revolved about its own axis is the principal part of the concrete mix- er shown in the accom- panying illus- tration. The mixer is to be used for the small job where a big mixer would be unnec- essary but where hand-mixing would be too slow and expensive to be considered.

The apparatus is operated by a one and one-half horsepower gasoline motor mount- ed on a portable carriage. It is especially adapted for the use of farmers or small con- tractors in the laying of concrete barn floors, house steps, sidewalks and the like.

The sand, cement and stone are shoveled into the barrel in the proper amounts. Then the barrel is revolved about its axis by a belt, driven from the motor, water being added to the mixture during the process. The chain sup- porting the barrel passes over two trunnion blocks at the top of the frame. These are con- nected by a bell-crank with a handle which can be pulled down for unloading.

��Sand, cement and stone are shoveled into the barrel in proper amounts and mixed by revolving the barrel on its axis, water being added during the process as needed


����What Poor Pavements Cost the Automobile Owner

running an elec- tric delivery wagon over pavements and measuring the amount of power required at dif- ferent speeds the condition of the pave- ment and its resistance to traction have been o b - tained. At the rate of twelve miles an hour it takes tw^enty per cent more power to run a car on a poor asphalt pavement than on a good one. On a poor, soft macadam pavement it takes one hundred and twenty-five per cent more power. This taxes each owner about twenty-five dollars annually for roads.

Eliminating the Bumps from the Motorcycle Ride

ONE of the largest American motor- cycle manufacturers has just brought out a stock model equipped with a hori- zontal opposed motor, which is designed to reduce vibration and thereby provide a smooth- ly running motorcycle at all speeds. The two- cylinder, four-cycle mo- tor has its cylinders placed fore and aft. As shown in the accom- panying cross-section fRONT view of the motor, lOTDR ^jjg crankpin ends of the connecting rods are attached to a one-piece balanced crankshaft. By this method of cylinder plac- ing, the vibration set up in one cylinder by the reciprocation of its pis- ton is offset by that in the opposite cylinder, and in this way the jolting of the motor- cycle is avoided.

��The new smoothly-running motorcycle from which the vibrations have been elimi- nated, and the cross- sectional view of the motor, showing the placing of the cylinders

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