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An illustration of angles with the same vertex made up of 4 lines.

Angles With Same Vertex

An illustration of angles with the same vertex made up of 4 lines.

Illustration showing if a straight line is perpendicular to one of two parallel lines, it is perpendicular to the other also.

Parallel Lines

Illustration showing if a straight line is perpendicular to one of two parallel lines, it is perpendicular…

"When any liquid is placed in one or more of several vessels communicating with each other, it will not come to rest until it stands at the same height inall of thw vessels. This principle is emobodied in the familiar expression 'Water seeks its level.' the principle is illustrated, on a large scale, in the system of pipes by which water is distributed in cities." -Avery 1895

Water Level in Multiple Connected Vessels

"When any liquid is placed in one or more of several vessels communicating with each other, it will…

"...represents two sets of sound waves with like periods and phases but different amplitudes." -Avery 1895

Waves with Different Amplitudes with Equal Periods

"...represents two sets of sound waves with like periods and phases but different amplitudes." -Avery…