Search results
Results from the WOW.Com Content Network
In both customary and imperial units, one foot comprises 12 inches, and one yard comprises three feet. Since an international agreement in 1959, the foot is defined as equal to exactly 0.3048 meters. Historically, the "foot" was a part of many local systems of units, including the Greek, Roman, Chinese, French, and English systems. It varied in ...
A nautical mile is a unit of length used in air, marine, and space navigation, and for the definition of territorial waters. [2] [3] [4] Historically, it was defined as the meridian arc length corresponding to one minute ( 1 / 60 of a degree) of latitude at the equator, so that Earth's polar circumference is very near to 21,600 nautical miles (that is 60 minutes × 360 degrees).
feet Metric US & Imperial Notes Taiwanese Hokkien Hakka Mandarin Character Exact Approx. Exact Approx. Hun: Fûn: Fēn: 分: 1 ⁄ 100 1 / 330 m: 3.030 mm 125 / 37,719 yd: 0.1193 in Same as Japanese Bu: Chhùn: Chhun: Cùn: 寸: 1 ⁄ 10 1 / 33 m: 3.030 cm 1250 / 37,719 yd: 1.193 in Taiwanese inch; Same as ...
This differs from many older systems in which the ratio of different units varied. For example, 12 inches is one foot, but the larger unit in the same system, the mile is not a power of 12 feet. It is 5,280 feet – which is hard to remember for many. [5]: 17
Before the establishment of the decimal metric system in France during the French Revolution in the late 18th century, [4] many units of length were based on parts of the human body. [5] [6] The Nippur cubit was one of the oldest known units of length. The oldest known metal standard for length corresponds to this Sumerian unit and dates from ...
A single graphic scale, of the sort on many maps, would therefore be useless on such a chart. Since the length of a nautical mile, for practical purposes, is equivalent to about a minute of latitude, a distance in nautical miles on a chart can easily be measured by using dividers and the latitude scales on the sides of the chart.
From 1630 to 1718 a millia was 5,564 feet (1,696 metres), making a geographical league of four millias equal 22,256 feet (6,784 m or 3.663 modern nautical miles). But from 1718 through the 1830s the millia was defined as the equivalent of just over 5,210 feet, giving a shorter geographical league of just over 20,842 feet (6,353 m or 3.430 ...
A person taking the test covers one eye from 6 metres or 20 feet away, and reads aloud the letters of each row, beginning at the top. The smallest row that can be read accurately indicates the visual acuity in that specific eye. The symbols on an acuity chart are formally known as "optotypes". Variation of Snellen chart with another letter ...