Clackamas County / Ë k l Ã¦ k É m Éª s / is a county in the U.S. state of Oregon. As of the 2010 census, the population was 375,992, making it Oregon's third-most populous county. Its county seat is Oregon City.
By 1850, this journey was halved. For instance the clipper ship Oriental was able to sail from Hong Kong to London in 97 days that year. The absolute one day distance record made by a clipper involved 436 nautical miles. Clipper ships were fast but no specific rig type was standard. By 1845, the term was used in conjunction with a name indicating the cargo carried or area served by a fast-sailing vessel and a specific rig type was usually indicated.
Afterward, the number of knots that had gone over the shipâs stern was counted and used in calculating the vesselâs rate of speed. A knot came to mean one nautical mile per hour. Therefore, a ship traveling at 15 knots could go 15 nautical miles per hour. For a number of years, there was disagreement among various nations about the exact measurement of a nautical mile, which is based on the Earthâs circumference.