A perennial stream or perennial river is a stream or river (channel) that has continuous flow in parts of its stream bed all year round during years of normal rainfall. "Perennial" streams are contrasted with "intermittent" streams which normally cease flowing for weeks or months each year, and with "ephemeral" channels that flow only for hours or days following rainfall.

On this date in 1776, rebellious colonials launched the first modern democracy, an experiment in government controlled by the people themselves. America succeeded so well that virtually the entire world later adopted democracy with its guarantee of personal rights.

Since 1944, the County of Los Angeles Department of Parks and Recreation has been meeting the diverse needs of not only residents, but also visitors from around the world. With over 63,000 acres of parks, gardens, lakes, trails, natural areas, and the world's largest public golf course system, the Department of Parks and Recreation is committed to providing the public with social, cultural, and recreational activities to enjoy the whole year.

The Scientific Services Bureau operates one of the largest full-service crime laboratories in the United States. A staff of 198 members provides forensic science support to all Los Angeles County law enforcement agencies, except the Los Angeles Police Department. Approximately one half of the nearly 70,000 cases submitted annually to the Crime Lab is from Sheriff's Department investigators , while the remainder is from local, state, and federal agencies. Since 1989 the Scientific Services Bureau has been an accredited laboratory through the American Society of Crime Laboratory Directors/Laboratory Accreditation Board (ASCLD/LAB).

Deadweight tonnage is a measure of how much weight a ship is carrying or can safely carry. It is the sum of the weights of cargo, fuel, fresh water, ballast water, provisions, passengers, and crew.