// #13. The Help of Inertia

Since the time of David many boys have swung pebbles by a string, or sling, and felt the pull of what we call a centrifugal (center-fleeing) force. David utilized it to one good purpose. Goliath was greatly surprised; such a thing never entered his head before. Whether a stone or an idea enters one's head depends on the kind of head he has.

We utilize this force in many ways now. Some boys swing a pail of milk over their heads, and if swung fast enough the centrifugal force overcomes the force of gravitation, and the milk does not fall. That is not utilizing the force. It often terrorizes the careful mother, anxious for the safety of the milk.

But in the arts of practical life we do utilize this force, which is only inertia.

Once it took a long time for molasses to drain out of a hogshead of damp sugar. Now it is put into a great tub, with holes in the side, which is made to revolve rapidly, and the molasses flies out. In the best laundries clothes are not wrung out, to the great damage of tender fabrics, but are put into such a tub and whirled nearly dry. So fifty yards of woolen cloth just out of the dye vat - who could wring it? It is coiled in a tub called a wizard, and whirled.

Muddy water is put through a process called clarification. It is the same, except that there are no holes in the vessel. The heavier particles of dirt, that would settle in time, take the outside, leaving perfectly clean water in the middle. A perpendicular perforated pipe, with a faucet below, drains off all the clear water and leaves all the mud. Milk is brought in from the milking and put into a separator; whirl it, and the heavier milk takes the outside of the whirling mass, and the lighter cream can be drawn off from the middle. It is far more perfectly separated than by any skimming.

A rotary snowplow slices off two feet of a ten-foot drift at each revolution, and by centrifugal force flings it out of the cutting with a speed that a hundred navvies or dagos cannot equal.

// #13. The Help of Inertia

Since the time of David many boys have swung pebbles by a string, or sling, and felt the pull of what we call a centrifugal (center-fleeing) force. David utilized it to one good purpose. Goliath was greatly surprised; such a thing never entered his head before. Whether a stone or an idea enters one's head depends on the kind of head he has.

We utilize this force in many ways now. Some boys swing a pail of milk over their heads, and if swung fast enough the centrifugal force overcomes the force of gravitation, and the milk does not fall. That is not utilizing the force. It often terrorizes the careful mother, anxious for the safety of the milk.

But in the arts of practical life we do utilize this force, which is only inertia.

Once it took a long time for molasses to drain out of a hogshead of damp sugar. Now it is put into a great tub, with holes in the side, which is made to revolve rapidly, and the molasses flies out. In the best laundries clothes are not wrung out, to the great damage of tender fabrics, but are put into such a tub and whirled nearly dry. So fifty yards of woolen cloth just out of the dye vat - who could wring it? It is coiled in a tub called a wizard, and whirled.

Muddy water is put through a process called clarification. It is the same, except that there are no holes in the vessel. The heavier particles of dirt, that would settle in time, take the outside, leaving perfectly clean water in the middle. A perpendicular perforated pipe, with a faucet below, drains off all the clear water and leaves all the mud. Milk is brought in from the milking and put into a separator; whirl it, and the heavier milk takes the outside of the whirling mass, and the lighter cream can be drawn off from the middle. It is far more perfectly separated than by any skimming.

A rotary snowplow slices off two feet of a ten-foot drift at each revolution, and by centrifugal force flings it out of the cutting with a speed that a hundred navvies or dagos cannot equal.